Adding the repo was no issue, haven't actually tried the build process yet.
Tho what I have been working on is trimming the image down. So far the compressed download has gone from about 2.2ishGB to 1.7ish. No Wayland, quite a bit of stuff removed, such as thonny, python libs that were related to the RPi development package. Modemmanger was removed, vnc taken out as cups was a dependency, which also takes 2 unneeded services out of the equation. Basically as much as I could find that wasn't really required to run a CNC machine. The image does have 2 desktop environments XFCE which is the default and RPi LXDE , you can swap via logging out and selecting the session from the login screen.
One thing that is annoying is that Linuxcnc appears under 3 different menu headings, whilst it is annoying is doesn't affect operation, this can be fixed by editing the desktop files deep in the system, this could get overwritten via upgrades. I'm considering using a 'hook' that is run when Linuxcnc is upgraded that fixes these annoying menu entries. Another "side project" to jump into.
This feels more like a blog now where I record ideas and changes hahaha
