Those look great.
Just an idea for a later update if it happens, add the opening width and the length of walls on the description info on each item. Also possibly some indication of opening direction/swing when placing via the ghost image if that's possible.
So they failed it because it took too many slots? Then they should have failed their whole game
Also those look really nice, cant wait to build with them, now we just need trees
It sounds like he added a feature to keep the slots down, and he said it failed without giving extra information, therefore I'm free to assume that he added more options to limit slots because it failed for too many slots.
He mentioned they failed 'due to his stupidity' doubt that's the slot count. And making assumption usually ends up with angry people, so ye. Don't make them, especially when they are most likely wrong.