I would love to hear more about your oddly-shaped non-rectangular room.
For now rectilinear has made things simpler; but on this kick now with 3d-printed jigs also derived from the spec. I already have a dog-hole system worked out and in-place with this idea. Could be interesting to extend to curves - becomes approachable/repeatable.
I would love to have floor to ceiling custom shelves. On my second floor I have ceilings that are angled instead of flat and would love to still have the usable space for books. Stuff like this is what I would love to make: