It would be great to have a tool like wall edge to define slab edges, this will solve a lot of time and extra walls beams for creating slab edge for balconies, floating slabs etc
niche and lésène : it would be helpfull for plan and section view to see the wall skin returns nside when placing a niche,
Your two wishes are unrelated to each other and hence should probably be in separate threads. Also, you should search the forum before making a post to prevent duplicates...