when Curt and I started this, it was to be a reproduction of the 1090XL expansion box, nothing more and nothing less. it is an open design and others can update it as they like but, when finished (if ever) then this will be a 1090XL expansion box as Atari was going to release (though they never did).
as I said though, this is an open design. Schematics and even the board layout gerbers are on github at https://github.com/kenames99 and anyone is free to do their own mods and produce that if they so choose too.
reifsnyderb did do a necessary update/modification to the main schematic to fully support the 130XE computers. it is completely compatible with the original design and intent. I just have not put that in the github yet. (sorry reifsnyderb).
Ken