Manuel,
I just wanted to make a good faith attempt to at least finish what was started, as far as arm64 work goes.
All it needs are symlinks to the arm64-specific bits in the lxqt-arm64 directory, and the symlinks used for the other two xfce builders. All other changes have been straightened out in the scripts. If you can do that, I can test them and let you know if they work...