diff --git a/multipass/cloud-init-rpios-like-arm64.yaml b/multipass/cloud-init-rpios-like-arm64.yaml
new file mode 100644
index 0000000..0e06770
--- /dev/null
+++ b/multipass/cloud-init-rpios-like-arm64.yaml
@@ -0,0 +1,62 @@
+#cloud-config
+hostname: rpios-like-arm64
+manage_etc_hosts: true
+
+write_files:
+  - path: /usr/local/sbin/setup-raspi-repo-and-sys-mods-arm64.sh
+    permissions: "0755"
+    content: |
+      #!/usr/bin/env bash
+      set -euo pipefail
+
+      arch="$(dpkg --print-architecture)"
+      if [[ "$arch" != "arm64" ]]; then
+        echo "arm64-only; detected '$arch' -> skipping" >&2
+        exit 0
+      fi
+
+      export DEBIAN_FRONTEND=noninteractive
+
+      apt-get update
+      apt-get install -y --no-install-recommends ca-certificates curl gnupg util-linux
+
+      install -d -m 0755 /usr/share/keyrings /etc/apt/preferences.d
+
+      if [[ ! -s /usr/share/keyrings/raspberrypi-archive-keyring.gpg ]]; then
+        curl -fsSL https://archive.raspberrypi.org/debian/raspberrypi.gpg.key \
+          | gpg --dearmor -o /usr/share/keyrings/raspberrypi-archive-keyring.gpg
+        chmod 0644 /usr/share/keyrings/raspberrypi-archive-keyring.gpg
+      fi
+
+      #cat >/etc/apt/preferences.d/raspi.pref <<'EOF'
+      #Package: *
+      #Pin: origin "archive.raspberrypi.org"
+      #Pin-Priority: 100
+      #EOF
+
+      if [[ ! -f /etc/apt/sources.list.d/raspi.sources ]]; then
+        cat >/etc/apt/sources.list.d/raspi.sources <<'EOF'
+      Types: deb
+      URIs: https://archive.raspberrypi.org/debian/
+      Suites: trixie
+      Components: main
+      Signed-By: /usr/share/keyrings/raspberrypi-archive-keyring.gpg
+      EOF
+      fi
+
+      apt-get update
+
+      # Add custom /etc/rpi-issue for "rpios-like"
+      if [[ ! -s /etc/rpi-issue ]]; then
+        {
+          echo "Raspberry Pi reference trixie-latest $(date -R)"
+          echo "Emulated using debian-13-genericcloud"
+        } >/etc/rpi-issue
+      fi
+
+      echo "---- /etc/rpi-issue ----"
+      cat /etc/rpi-issue || true
+      echo "------------------------"
+
+runcmd:
+  - [ bash, -lc, "/usr/local/sbin/setup-raspi-repo-and-sys-mods-arm64.sh" ]
diff --git a/multipass/run_parallel_iiab_test.sh b/multipass/run_parallel_iiab_test.sh
index 4d6c26a..8a39dd4 100644
--- a/multipass/run_parallel_iiab_test.sh
+++ b/multipass/run_parallel_iiab_test.sh
@@ -7,7 +7,6 @@
 #   --clean                      Stop+delete+purge target VMs (by BASE-<number>, regardless of COUNT)
 # Distro selection:
 #   --debian-13          Debian 13 only (sets IMAGE=$DEBIAN13_IMAGE_URL and BASE=deb13)
-#   --debian-13          Debian 13 only (sets IMAGE=$DEBIAN13_IMAGE_URL and BASE=deb13)
 #   --both-distros       Run Ubuntu + Debian 13 in parallel: COUNT=N => 2N VMs (default order: interleaved)
 #   --first-ubuntu       (with --both-distros) order: all Ubuntu first, then all Debian
 #   --first-debian       (with --both-distros) order: all Debian first, then all Ubuntu
@@ -16,6 +15,11 @@
 #   --pr 4122            (repeatable) add PR numbers passed to install.txt
 #   --run-pr 4122        same as --pr but also forces --run (alias: --test-pr)
 #
+# Cloud-init:
+#   --cloud-init FILE        Apply cloud-init FILE to all VMs (Ubuntu + Debian)
+#   --cloud-init-rpios       Apply RaspberryPiOS-style cloud-init only to Debian side
+#                            (alias of --debian-13, but sets Debian BASE=rpios-d13)
+#
 # Env vars:
 #   IIAB_PR="4122 4191"          Space-separated PRs
 #   (compat) IIAB_INSTALL_ARGS   If set, used as fallback for IIAB_PR
@@ -34,12 +38,21 @@
 set -euo pipefail
 
 DPKG_ARCH="$(dpkg --print-architecture)"
+
+# Resolve paths relative to this script (so cloud-init files work from any cwd)
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
+
 # Debian 13 (Trixie) official cloud image (qcow2). Multipass can launch from URL/file:// on Linux.
 # Source: Debian cloud images live under cloud.debian.org/images/cloud/ ('genericcloud' includes cloud-init).
 DEBIAN13_IMAGE_URL="${DEBIAN13_IMAGE_URL:-https://cloud.debian.org/images/cloud/trixie/latest/debian-13-genericcloud-${DPKG_ARCH}.qcow2}"
 
 IMAGE="${IMAGE:-24.04}"
 BASE="${BASE:-ubu2404}"
+# cloud-init controls
+CLOUD_INIT_FILE="${CLOUD_INIT_FILE:-}"
+RPIOS_CLOUD_INIT_FILE="${RPIOS_CLOUD_INIT_FILE:-$SCRIPT_DIR/cloud-init-rpios-like-arm64.yaml}"
+DEB_CLOUD_INIT_FILE="${DEB_CLOUD_INIT_FILE:-}"
+RPIOS_MODE=0
 COUNT="${COUNT:-1}"
 [ "$DPKG_ARCH" = "arm64" ] && CPUS="${CPUS:-2}" # SBC don't have spare CPUs.
 [ "$DPKG_ARCH" = "amd64" ] && CPUS="${CPUS:-3}"
@@ -54,7 +67,7 @@ LOCAL_VARS_URL="${LOCAL_VARS_URL:-https://raw.githubusercontent.com/iiab/iiab/re
 
 WAIT_TRIES="${WAIT_TRIES:-60}"     # used ONLY for the first auto-resume
 WAIT_SLEEP="${WAIT_SLEEP:-5}"
-STAGGER="${STAGGER:-20}"
+STAGGER="${STAGGER:-30}"
 RESUME_TRIES="${RESUME_TRIES:-3}"
 RESUME_RETRY_SLEEP="${RESUME_RETRY_SLEEP:-8}"
 
@@ -91,6 +104,10 @@ Image shortcuts:
   --first-ubuntu  With --both-distros: run all Ubuntu first, then Debian
   --first-debian  With --both-distros: run all Debian first, then Ubuntu
 
+Cloud-init:
+  --cloud-init FILE     Apply FILE to all VMs
+  --cloud-init-rpios    Apply rpios cloud-init only to Debian side; BASE=rpios-d13 (Debian)
+
 PR options:
   --pr N        Add PR number (repeatable)
   --run-pr N    Add PR number and force --run
@@ -111,12 +128,25 @@ while [[ $# -gt 0 ]]; do
     --first-ubuntu) FIRST_UBUNTU=1; shift ;;
     --first-debian) FIRST_DEBIAN=1; shift ;;
 
+    --cloud-init)
+      [[ $# -lt 2 ]] && { echo "[ERROR] --cloud-init needs a file path"; exit 2; }
+      CLOUD_INIT_FILE="$2"; shift 2 ;;
+
     --debian-13)
       DEBIAN13_ONLY=1
       IMAGE="$DEBIAN13_IMAGE_URL"
       BASE="deb13"
       shift ;;
 
+    --cloud-init-rpios)
+      # Debian-only rpios flavor: also implies Debian 13 selection
+      DEBIAN13_ONLY=1
+      RPIOS_MODE=1
+      IMAGE="$DEBIAN13_IMAGE_URL"
+      BASE="rpios-d13"
+      DEB_CLOUD_INIT_FILE="$RPIOS_CLOUD_INIT_FILE"
+      shift ;;
+
     --module)
       [[ $# -lt 2 ]] && { echo "[ERROR] --module needs a value"; exit 2; }
       modules+=("$2"); shift 2 ;;
@@ -139,7 +169,7 @@ while [[ $# -gt 0 ]]; do
   esac
 done
 
-# ---- Incoherency checks (fail fast) ----
+#  Incoherency checks (fail fast)
 if [[ "$FIRST_UBUNTU" == "1" && "$FIRST_DEBIAN" == "1" ]]; then
   echo "[ERROR] Incoherent options: --first-ubuntu and --first-debian cannot be used together."
   exit 2
@@ -149,7 +179,31 @@ if [[ ( "$FIRST_UBUNTU" == "1" || "$FIRST_DEBIAN" == "1" ) && "$BOTH_DISTROS" !=
   echo "[ERROR] --first-ubuntu/--first-debian requires --both-distros."
   exit 2
 fi
-# ----
+
+if ! [[ "${COUNT}" =~ ^[0-9]+$ ]] || (( COUNT < 1 )); then
+  echo "[ERROR] COUNT must be an integer >= 1 (got: '${COUNT}')" >&2
+  exit 2
+fi
+# ---
+
+# Fail-fast validation for cloud-init files
+if [[ -n "${CLOUD_INIT_FILE:-}" && ! -f "$CLOUD_INIT_FILE" ]]; then
+  echo "[ERROR] --cloud-init file not found on host: $CLOUD_INIT_FILE" >&2
+  exit 2
+fi
+
+if [[ -n "${DEB_CLOUD_INIT_FILE:-}" && ! -f "$DEB_CLOUD_INIT_FILE" ]]; then
+  echo "[ERROR] Debian cloud-init file not found on host: $DEB_CLOUD_INIT_FILE" >&2
+  exit 2
+fi
+
+# RPiOS flavor is meant for arm64 (rpios-like). Fail fast to avoid surprising runs.
+if [[ "$RPIOS_MODE" == "1" && "$DPKG_ARCH" != "arm64" ]]; then
+  echo "[ERROR] --cloud-init-rpios is intended for arm64 hosts (detected: $DPKG_ARCH)." >&2
+  echo "        If you really want to run it on non-arm64, pass a normal --cloud-init FILE instead." >&2
+  exit 2
+fi
+# ---
 
 # Default module
 if [[ "${#modules[@]}" -eq 0 ]]; then
@@ -169,6 +223,7 @@ if [[ "$BOTH_DISTROS" == "1" ]]; then
   UBU_BASE="$UBU_BASE_ORIG"
   DEB_IMAGE="$DEBIAN13_IMAGE_URL"
   DEB_BASE="deb13"
+  [[ "$RPIOS_MODE" == "1" ]] && DEB_BASE="rpios-d13"
 else
   UBU_IMAGE="$IMAGE"
   UBU_BASE="$BASE"
@@ -214,12 +269,13 @@ wait_all() {
 # Escape BASE for regex usage
 re_escape() { printf '%s' "$1" | sed -e 's/[].[^$*+?(){}|\\]/\\&/g'; }
 
-declare -A VM_IMAGE
+declare -A VM_IMAGE VM_CLOUD_INIT
 names=()
 
 build_vm_lists() {
   names=()
   VM_IMAGE=()
+  VM_CLOUD_INIT=()
 
   if [[ "$BOTH_DISTROS" == "1" ]]; then
     if [[ "$FIRST_UBUNTU" == "1" ]]; then
@@ -228,11 +284,13 @@ build_vm_lists() {
         local u="${UBU_BASE}-${n}"
         names+=("$u")
         VM_IMAGE["$u"]="$UBU_IMAGE"
+        VM_CLOUD_INIT["$u"]="$CLOUD_INIT_FILE"
       done
       for n in $(seq 0 $((COUNT-1))); do
         local d="${DEB_BASE}-${n}"
         names+=("$d")
         VM_IMAGE["$d"]="$DEB_IMAGE"
+        VM_CLOUD_INIT["$d"]="${DEB_CLOUD_INIT_FILE:-$CLOUD_INIT_FILE}"
       done
 
     elif [[ "$FIRST_DEBIAN" == "1" ]]; then
@@ -241,11 +299,13 @@ build_vm_lists() {
         local d="${DEB_BASE}-${n}"
         names+=("$d")
         VM_IMAGE["$d"]="$DEB_IMAGE"
+        VM_CLOUD_INIT["$d"]="${DEB_CLOUD_INIT_FILE:-$CLOUD_INIT_FILE}"
       done
       for n in $(seq 0 $((COUNT-1))); do
         local u="${UBU_BASE}-${n}"
         names+=("$u")
         VM_IMAGE["$u"]="$UBU_IMAGE"
+        VM_CLOUD_INIT["$u"]="$CLOUD_INIT_FILE"
       done
 
     else
@@ -256,6 +316,8 @@ build_vm_lists() {
         names+=("$u" "$d")
         VM_IMAGE["$u"]="$UBU_IMAGE"
         VM_IMAGE["$d"]="$DEB_IMAGE"
+        VM_CLOUD_INIT["$u"]="$CLOUD_INIT_FILE"
+        VM_CLOUD_INIT["$d"]="${DEB_CLOUD_INIT_FILE:-$CLOUD_INIT_FILE}"
       done
     fi
   else
@@ -263,6 +325,11 @@ build_vm_lists() {
       local vm="${BASE}-${n}"
       names+=("$vm")
       VM_IMAGE["$vm"]="$IMAGE"
+      if [[ "$DEBIAN13_ONLY" == "1" ]]; then
+        VM_CLOUD_INIT["$vm"]="${DEB_CLOUD_INIT_FILE:-$CLOUD_INIT_FILE}"
+      else
+        VM_CLOUD_INIT["$vm"]="$CLOUD_INIT_FILE"
+      fi
     done
   fi
 }
@@ -320,14 +387,20 @@ cleanup_vms() {
 launch_one() {
   local vm="$1"
   local img="${VM_IMAGE[$vm]:-}"
-  [[ -z "$img" ]] && { echo "[ERROR] No image mapping for VM '$vm'"; return 2; }
+  [[ -n "$img" ]] || { echo "[ERROR] No image mapping for VM '$vm'"; return 2; }
+
+  # Cloud-init file to apply (already validated earlier in fail-fast checks)
+  local ci="${VM_CLOUD_INIT[$vm]:-}"
+  local -a ci_args=()
+  [[ -n "${ci:-}" ]] && ci_args=(--cloud-init "$ci")
 
   if vm_exists "$vm"; then
     echo "[INFO] VM already exists: $vm"
     return 0
   fi
+
   echo "[INFO] Launching $vm ..."
-  multipass launch "$img" -n "$vm" -c "$CPUS" -m "$MEM" -d "$DISK" >/dev/null
+  multipass launch "$img" -n "$vm" -c "$CPUS" -m "$MEM" -d "$DISK" "${ci_args[@]}" >/dev/null
 }
 
 run_install_txt() {
@@ -337,6 +410,17 @@ run_install_txt() {
   log="$LOGROOT/${vm}.install.${t}.log"
   rc="$LOGROOT/${vm}.install.${t}.rc"
 
+  echo "[INFO] Waiting for VM readiness before install: $vm"
+  if ! wait_for_vm "$vm"; then
+    {
+      echo "[INFO] Waiting for VM readiness before install: $vm"
+      echo "[ERROR] VM did not become ready in time (install phase): $vm"
+    } >"$log"
+    echo "88" >"$rc"
+    set_latest_links "$vm" "install" "$log" "$rc"
+    return 88
+  fi
+
   echo "[INFO] install.txt in $vm (log $(basename "$log")) ..."
 
   local modules_str pr_str
@@ -423,7 +507,7 @@ run_install_txt() {
 
 resume_iiab() {
   local vm="$1"
-  local do_long_wait="$2"   # 1 => wait_for_vm (only for first auto-resume), 0 => no long wait
+  local do_long_wait="$2"
   local t log rc
   t="$(stamp)"
   log="$LOGROOT/${vm}.resume.${t}.log"
@@ -432,7 +516,7 @@ resume_iiab() {
   echo "[INFO] resume (iiab -f) in $vm (log $(basename "$log")) ..."
 
   set +e
-  {
+  (
     multipass start "$vm" >/dev/null 2>&1 || true
 
     if [[ "$do_long_wait" == "1" ]]; then
@@ -445,7 +529,6 @@ resume_iiab() {
 
     # Retry on rc=255 (SSH connection dropped; often reboot/network restart during apt/upgrade)
     # Also neutralize apt-listchanges/pagers to avoid "Waiting for data..." stalls.
-    local attempt r
     r=1
     for attempt in $(seq 1 "$RESUME_TRIES"); do
       echo "[INFO] Resume attempt ${attempt}/${RESUME_TRIES} on $vm"
@@ -493,7 +576,7 @@ resume_iiab() {
     done
 
     exit "$r"
-  } >"$log" 2>&1
+  ) >"$log" 2>&1
   echo "$?" >"$rc"
   set -e
 
@@ -510,9 +593,7 @@ summary() {
     [[ -f "$LOGROOT/latest.${vm}.install.rc" ]] && ir="$(cat "$LOGROOT/latest.${vm}.install.rc" 2>/dev/null || echo n/a)"
     [[ -f "$LOGROOT/latest.${vm}.resume.rc"  ]] && rr="$(cat "$LOGROOT/latest.${vm}.resume.rc"  2>/dev/null || echo n/a)"
 
-    printf "%-12s %-8s %-8s %s\n" \
-      "$vm" "$ir" "$rr" \
-      "latest.${vm}.install.log / latest.${vm}.resume.log"
+    printf "%-12s %-8s %-8s %s\n" "$vm" "$ir" "$rr" "latest.${vm}.install.log / latest.${vm}.resume.log"
   done
 
   echo
@@ -561,7 +642,7 @@ pipeline_parallel_stagger() {
       run_install_txt "$vm"
       # Only Ubuntu tends to reboot during install; Debian often doesn't.
       local waitflag=1
-      if [[ "${VM_IMAGE[$vm]}" == "$DEBIAN13_IMAGE_URL" ]]; then
+      if [[ "$vm" == deb13-* ]]; then
         waitflag=0
       fi
       resume_iiab "$vm" "$waitflag"