diff --git a/Dockerfile b/Dockerfile
index 588026c..67c8e0c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,6 @@
 
 # Use the official Void Linux container
 FROM ghcr.io/void-linux/void-glibc-full 
-LABEL org.opencontainers.image.source=https://github.com/midzelis/zquickinit
 
 ARG XBPS_REPOS="https://repo-fastly.voidlinux.org/current https://repo-fastly.voidlinux.org/current/nonfree"
 
diff --git a/zquickinit.sh b/zquickinit.sh
index bf048e7..2865414 100755
--- a/zquickinit.sh
+++ b/zquickinit.sh
@@ -27,12 +27,24 @@ SRC_ROOT=${DIR}
 ZBM_ROOT=${SRC_ROOT}/../zfsbootmenu
 RECIPES_ROOT=${RECIPES_ROOT:-${SRC_ROOT}/recipes}
 
-RECIPE_BUILDER="ghcr.io/midzelis/zquickinit"
-ZQUICKEFI_URL="https://github.com/midzelis/zquickinit/releases/latest"
-# if empty, use latest release tag
-ZBM_TAG=
+RECIPE_BUILDER="${RECIPE_BUILDER:-ghcr.io/midzelis/zquickinit}"
+ZQUICKINIT_REPO="${ZQUICKINIT_REPO:-https://github.com/midzelis/zquickinit}"
+ZQUICKEFI_URL="${ZQUICKEFI_URL:-${ZQUICKINIT_REPO}/releases/latest}"
+
+# provide default stable, latest ZBM_TAG if not specified
+ZBM_TAG="${ZBM_TAG:-v3.0.1}"
+# if empty, then unset to get latest release
+if [[ -z "$ZBM_TAG" ]]; then
+	ZBM_TAG=""
+fi
+
 # if specified, takes precedence over ZBM_TAG
-ZBM_COMMIT_HASH=db78c980f40937f3b4de8d85e7430f6553a39972
+ZBM_COMMIT_HASH="${ZBM_COMMIT_HASH:-}"
+# if ZBM_COMMIT_HASH is specified, unset ZBM_TAG
+if [[ -n "$ZBM_COMMIT_HASH" ]]; then
+	ZBM_TAG=""
+fi
+
 INPUT=/input
 OUTPUT=/output
 ADD_LOADER=
@@ -40,8 +52,10 @@ MKINIT_VERBOSE=
 KERNEL_BOOT=
 ENGINE=
 OBJCOPY=
+DU=
 FIND=
 YG=
+STAT=
 NOASK=0
 DEBUG=0
 ENTER=0
@@ -101,10 +115,10 @@ check() {
 		fi
 	fi
 	if [[ $1 == docker || $1 == podman ]]; then
-		if command -v docker &>/dev/null; then
+		if [ -z "$ENGINE" ] && command -v docker &>/dev/null; then
 			ENGINE=docker
 			return 0
-		elif command -v podman &>/dev/null; then
+		elif [ -z "$ENGINE" ] && command -v podman &>/dev/null; then
 			ENGINE=podman
 			return 0
 		fi
@@ -142,17 +156,6 @@ check() {
 			OBJCOPY=objcopy
 		fi
 	fi
-	if ! command -v "$1" &>/dev/null; then
-		echo "$1 not found. usually part of the $2 package"
-		if [[ $1 == "gum" && -f "/etc/debian_version" ]]; then
-			echo "To install, try:"
-			echo 'sudo mkdir -p /etc/apt/keyrings'
-			echo 'curl -fsSL https://repo.charm.sh/apt/gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/charm.gpg'
-			echo 'echo "deb [signed-by=/etc/apt/keyrings/charm.gpg] https://repo.charm.sh/apt/ * *" | sudo tee /etc/apt/sources.list.d/charm.list'
-			echo 'sudo apt update && sudo apt install gum'
-		fi
-		exit 1
-	fi
 	if [[ $1 == find ]] && [[ -z "${FIND}" ]]; then
 		if command -v gfind &>/dev/null; then
 			FIND="gfind"
@@ -168,6 +171,47 @@ check() {
 			exit 1
 		fi
 	fi
+	if [[ $1 == du ]] && [[ -z "${DU}" ]]; then
+		if command -v gdu &>/dev/null; then
+			DU="gdu"
+		else
+			DU="du"
+		fi
+		if [[ ! "$(${DU} --version 2>&1 | head -n1)" == *GNU* ]]; then
+			echo "du must be GNU flavored. Update or install coreutils package. "
+			if [[ "$OSTYPE" == "darwin"* ]]; then
+				echo "On MacOS, use brew to install coreutils"
+				echo "Note: brew uses /usr/local/bin on Intel, and /opt/homebrew/bin on Apple"
+			fi
+			exit 1
+		fi
+	fi
+	if [[ $1 == stat ]] && [[ -z "${STAT}" ]]; then
+		if command -v gstat &>/dev/null; then
+			STAT="gstat"
+		else
+			STAT="stat"
+		fi
+		if [[ ! "$(${STAT} --version 2>&1 | head -n2)" =~ (GNU|BusyBox) ]]; then
+			echo "stat must be GNU or BusyBox flavored. Update or install coreutils package."
+			if [[ "$OSTYPE" == "darwin"* ]]; then
+				echo "On MacOS, use brew to install coreutils"
+				echo "Note: brew uses /usr/local/bin on Intel, and /opt/homebrew/bin on Apple"
+			fi
+			exit 1
+		fi
+	fi
+	if ! command -v "$1" &>/dev/null; then
+		echo "$1 not found. usually part of the $2 package"
+		if [[ $1 == "gum" && -f "/etc/debian_version" ]]; then
+			echo "To install, try:"
+			echo 'sudo mkdir -p /etc/apt/keyrings'
+			echo 'curl -fsSL https://repo.charm.sh/apt/gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/charm.gpg'
+			echo 'echo "deb [signed-by=/etc/apt/keyrings/charm.gpg] https://repo.charm.sh/apt/ * *" | sudo tee /etc/apt/sources.list.d/charm.list'
+			echo 'sudo apt update && sudo apt install gum'
+		fi
+		exit 1
+	fi
 }
 
 # This will build the main ZquickInit Builder OCI image
@@ -197,6 +241,7 @@ builder() {
 	echo
 	cmd=("$ENGINE" build .
 		-t "$RECIPE_BUILDER"
+		--label org.opencontainers.image.source="${ZQUICKINIT_REPO}"
 		--build-arg KERNELS=linux6.6
 		--build-arg "PACKAGES=${packages[*]}"
 		--build-arg ZBM_COMMIT_HASH="${ZBM_COMMIT_HASH}"
@@ -225,6 +270,7 @@ tailscale() {
 make_zquick_initramfs() {
 	check gum gum
 	check mkinitcpio mkinitcpio
+	check stat stat
 
 	gum style --bold --border double --align center \
 		--width 50 --margin "1 2" --padding "0 2" "Welcome to ZQuickInit make initramfs"
@@ -234,13 +280,13 @@ make_zquick_initramfs() {
 		local hash
 		echo "Downloading zquickinit"
 		rm -rf "${INPUT}"
-		git clone --quiet --depth 1 https://github.com/midzelis/zquickinit.git "${INPUT}"
+		git clone --quiet --depth 1 "${ZQUICKINIT_REPO}" "${INPUT}"
 		hash=$(cat /etc/zquickinit-commit-hash || echo '')
 		if [[ -n "${hash}" ]]; then
 			(cd "${INPUT}" && git fetch --depth 1 origin "$hash" && git checkout FETCH_HEAD)
 		fi
 	fi
-	[[ -x /etc/zquickinit-commit-hash ]] && (cd "${INPUT}" && git config --global --add safe.directory "${INPUT}" && /etc/zquickinit-commit-hash && git rev-parse HEAD >/etc/zquickinit-commit-hash && echo "ZQuickInit (https://github.com/midzelis/zquickinit) commit hash: $(git rev-parse --short HEAD) ($(git rev-parse HEAD))")
+	[[ -x /etc/zquickinit-commit-hash ]] && (cd "${INPUT}" && git config --global --add safe.directory "${INPUT}" && /etc/zquickinit-commit-hash && git rev-parse HEAD >/etc/zquickinit-commit-hash && echo "ZQuickInit (${ZQUICKINIT_REPO}) commit hash: $(git rev-parse --short HEAD) ($(git rev-parse HEAD))")
 
 	if [[ ! -f "${ZBM}/bin/generate-zbm" ]]; then
 		echo "Downloading latest zfsbootmenu"
@@ -576,9 +622,9 @@ make_zquick_initramfs() {
 	)
 	chmod o+rw -R "${OUTPUT}"/*
 	chmod g+rw -R "${OUTPUT}"/*
-	env LC_ALL=en_US.UTF-8 printf "Kernel size: \t\t%'.0f bytes\n" "$(stat -c '%s' "${OUTPUT}/zquickinit-$build_time.vmlinuz-$kernel")"
-	env LC_ALL=en_US.UTF-8 printf "initramfs size: \t%'.0f bytes\n" "$(stat -c '%s' "$output_img")"
-	env LC_ALL=en_US.UTF-8 printf "EFI size: \t\t%'.0f bytes\n" "$(stat -c '%s' "$output_uki")"
+	env LC_ALL=en_US.UTF-8 printf "Kernel size: \t\t%'.0f bytes\n" "$(${STAT} -c '%s' "${OUTPUT}/zquickinit-$build_time.vmlinuz-$kernel")"
+	env LC_ALL=en_US.UTF-8 printf "initramfs size: \t%'.0f bytes\n" "$(${STAT} -c '%s' "$output_img")"
+	env LC_ALL=en_US.UTF-8 printf "EFI size: \t\t%'.0f bytes\n" "$(${STAT} -c '%s' "$output_uki")"
 	find "${OUTPUT}" -name 'zquickinit*.img' | sort -r | tail -n +4 | xargs -r rm
 	find "${OUTPUT}" -name 'zquickinit*.efi' | sort -r | tail -n +4 | xargs -r rm
 	find "${OUTPUT}" -name 'zquickinit*.vmlinuz-*' | sort -r | tail -n +4 | xargs -r rm
@@ -631,7 +677,7 @@ getefi() {
 		echo "No image found, finding latest release..."
 		local version='' download=''
 		version=$(curl --silent -qI "${ZQUICKEFI_URL}" | awk -F '/' '/^location/ {print  substr($NF, 1, length($NF)-1)}')
-		download="https://github.com/midzelis/zquickinit/releases/download/$version/zquickinit.efi"
+		download="${ZQUICKINIT_REPO}/releases/download/$version/zquickinit.efi"
 		source="${tmp}/zquickinit-${version}.efi"
 		echo "Downloading from ${download} to ${source}..."
 		curl -o "$source" --progress-bar -L "${download}"
@@ -736,6 +782,7 @@ inject() {
 		check bsdtar "libarchive-tools"
 		check objcopy binutils
 		check truncate coreutils
+		check stat coreutils
 		check find findutils
 
 		echo "Secrets were injected, appending '_injected' to name"
@@ -753,7 +800,7 @@ inject() {
 		# To append an additional initrd segment, the new archive must aligned to a
 		# 4-byte boundary: https://unix.stackexchange.com/a/737219
 
-		initrd_size=$(stat -c '%s' "${initrd}")
+		initrd_size=$(${STAT} -c '%s' "${initrd}")
 		initrd_size=$(((initrd_size + 3) / 4 * 4))
 		truncate -s "${initrd_size}" "${initrd}"
 
@@ -829,6 +876,7 @@ iso() {
 	check xorriso xorriso
 	check truncate coreutils
 	check find findutils
+	check du coreutils
 
 	local target=${1:-zquickinit.iso}
 	local source=${2:-}
@@ -844,7 +892,7 @@ iso() {
 	local isoroot="${tmp}/iso"
 	mkdir -p "${isoroot}"
 	local size
-	read -ra size <<<"$(du --apparent-size --block-size=1M "$source")"
+	read -ra size <<<"$(${DU} --apparent-size --block-size=1M "$source")"
 	local padded=$((size[0] + 12))
 	local part_img="${tmp}/efs_partition.img"
 	rm -rf "${part_img}"
@@ -878,6 +926,7 @@ playground() {
 	check truncate coreutils
 	check qemu-system-x86_64 qemu
 	check find findutils
+	check nproc coreutils
 
 	# shellcheck disable=SC2155
 	local tmp=$(tmpdir)
@@ -1101,6 +1150,12 @@ if [[ $(type -t "$command") == function ]]; then
 				shift
 			fi
 			;;
+		--engine)
+			if [[ -n ${2:-} ]]; then
+				ENGINE=$2
+				shift
+			fi
+			;;
 		--no-container)
 			NOCONTAINER=1
 			;;
@@ -1188,6 +1243,7 @@ else
 	echo "    --no-container Do not use containers to build initramfs"
 	echo "    --release     Do not add QEMU debug, or any secrets"
 	echo "    --secrets <dir> Use this folder for secrets."
+	echo "    --engine  <docker|podman> Override automatic detection to use specific engine."
 	echo "    -d,--debug    Advanced: Turn on tracing"
 	echo "    -e,--enter    Advanced: Do not build an image. Execute bash and"
 	echo "                  enter the builder image."