Below is the process to Remaster Debian Based Linux using only: gparted (or dd file fill) and mksqushfs 

Glad to see you are interested in my way to Remaster Debian Linux Custom Builds. My way is limited to just creating a filesystem.squashfs file which is compatible with Calamares Installer on at least Debian Linux LXDE and XFce Live Installer. I have also successfully installed using Q4OS5 KDE Live Installer with the "Pure" option. Additional Distro testing still needs to be done and if you do successfully use other Distro / Calamares installers, please let me know and I will add them to the list.

I created my simple Remaster process because the only remaster system that can be used by new Linux users is penguins-eggs. penguins-eggs works with Debian, Ubuntu, Arch, and other Distros. It also has many advanced features which only makes it too complicated for new Linux users.

Sumamry of my Remaster Linux process:

1. Prevent mksquashfs from capturing free space:

Option A:   Use gparted to shrink source parition +1 MB (Preferred, faster)

Option B: Write zero filled file to occupy free space of partition and then exclude same file from Remaster by mksquashfs command.

2. Mount Source and Target Patitions

Source:  The unmounted partition you want to remaster

Target: Where the filesystem.squahfs file will be written.

3. Use Calamares Installer of OEM Distro or penguins-eggs Remastered distro

    to install your custom build filesystem.squashfs file. 

sudo apt-get install gstreamer1.0-plugins-good

sudo apt-get install gstreamer1.0-libav 

sudo apt-get install gstreamer1.0-alsa 

sudo apt-get install gstreamer1.0-pulseaudio

sudo libgl1-mesa-dri

Resolution:

sudo apt install gstreamer1.0-plugins-bad

Resolution:

sudo apt-get install libgtksourceview-3.0-1 

sudo apt-get install libgtksourceview-3.0-common 

sudo apt-get install libgtksourceview-3.0-dev

Resolution:

sudo apt-get install libwebkit2gtk-4.0 

sudo apt-get install libwebkit2gtk-4.0-dev

[Compile yad 12.0  with --enable-html]

autoreconf -ivf && intltoolize

-> ./configure --enable-html --enable-sourceview

-> make

-> make install

-> gtk-update-icon-cache

-> exit

Resolution:

 add this to the bottom of /etc/apt/sources.list

 deb http://deb.debian.org/debian buster-backports main

 sudo atp-get update

Then install: sudo apt-get install libgtksourceview-3.0-dev

Issue 6A: mp4 will not execute via yad script - error= no xapp package

Resolution:

sudo apt-get install libxapp-gtk3-module



Issue 6B: mp4 will not display via yad script (same error as previouse verision)

Resolution:

sudo apt-get install gstreamer1.0-libav

 

sudo apt-get install -y libglib2.0-dev libgtk-3-dev

GRUB_DISABLE_OS_PROBER="false"

sudo apt-get install --reinstall intel-media-va-driver:amd64

sudo apt-get install --reinstall $(dpkg -l | grep ^ii | grep -i intel | awk '{print $2}')

sudo apt install xapp-sn-watcher libxapp-gtk3-module