Please ignore, I did what seemed most simple and plucked the functions I needed from the script and that seems to work.
#! /bin/bash function enable_plymouth_theme() { if [[ -z "$1" ]]; then echo "--------------------------------------------------------------------------------" echo "| Skipping Plymouth boot splash because no theme name was provided" echo "--------------------------------------------------------------------------------" echo -e "Skipped\n\n" return 255 fi PLYMOUTH_THEME=$1 echo "--------------------------------------------------------------------------------" echo "| Installing Plymouth boot splash and enabling theme '$PLYMOUTH_THEME'" echo "--------------------------------------------------------------------------------" apt-get install -y $APT_RECOMMENDS plymouth plymouth-themes plymouth-x11 rm -rf /tmp/plymouth-themes git clone --depth=1 https://github.com/HerbFargus/plymouth-themes.git /tmp/plymouth-themes mv /tmp/plymouth-themes/* /usr/share/plymouth/themes/ update-alternatives --install /usr/share/plymouth/themes/default.plymouth default.plymouth /usr/share/plymouth/themes/$PLYMOUTH_THEME/$PLYMOUTH_THEME.plymouth 10 update-alternatives --set default.plymouth /usr/share/plymouth/themes/$PLYMOUTH_THEME/$PLYMOUTH_THEME.plymouth update-initramfs -u echo -e "FINISHED enable_plymouth_theme \n\n" sleep 2 } # Hide Boot Messages function hide_boot_messages() { echo "--------------------------------------------------------------------------------" echo "| Hiding boot messages" echo "--------------------------------------------------------------------------------" # Hide kernel messages and blinking cursor via GRUB sed -i 's/GRUB_CMDLINE_LINUX_DEFAULT=".*"/GRUB_CMDLINE_LINUX_DEFAULT="quiet splash vt.global_cursor_default=0"/g' /etc/default/grub update-grub # Hide fsck messages after Plymouth splash echo 'FRAMEBUFFER=y' > /etc/initramfs-tools/conf.d/splash update-initramfs -u # Remove cloud-init to suppress its boot messages apt-get purge cloud-init -y rm -rf /etc/cloud/ /var/lib/cloud/ # Disable motd touch $USER_HOME/.hushlogin chown $USER:$USER $USER_HOME/.hushlogin echo -e "FINISHED hide_boot_messages \n\n" sleep 2 } enable_plymouth_theme "retropie-pacman" # See https://github.com/HerbFargus/plymouth-themes.git for other theme names hide_boot_messages