I got an XFCE desktop, and could run chromium on it !
Still a lot to configure to make it easier to use (fonts size mostly), I will probably try i3 but I need to learn it again, I only tested it once a while ago.

I didn't succeed with Debian Sid. It looks like the Xwayland compilation failed due to some dependancies. Not sure if it is due to mistakes on my part, or changes made in it (it is Sid after all, so changes can break things). I have seen the error by running every command of the script one by one from a terminal, as when running from the UI I didn't get a grasp of errors if any. Is there a log somewhere that can be checked after the UI run the script and the terminal disappeared ?

I tried again with Debian Buster, and I got to the end. I think I had to run some scripts manually, but didn't really take notes, I am still trying to understand what everything does.

For fun, I also try Fedora 32. It installed quickly, and command line works as expected. Seeing now a bit more how the scripts works on Debian, I think it is in my reach to port those to Fedora/CentOS. I will keep you updated if I try that and have some success.