As a hobbyist, when I make plans they are for "real" manufacturers (carpenters in my case). So my plans are not accurate for manufacturing. In particular, there is no tolerance / clearance gaps. This makes the dimensions "clean" (e.g. 40 cm doors are not 39.8). And the real manufacturer knows to make the required adjustments. But when it comes to rendering, this means that bodies that are adjacent to each other are rendered as one surface.
It would be useful to be able to mark some edges as 'gaps' in the render environment so they are rendered closer to the end real world outcome. E.g. in a closet, these would be between the doors, and between the doors and the frame. Another similar thing is fillets: for sure I can fillet my whole design, but I don't trust myself to use the right dimensions (and once I do, the manufacturer will use them as-is with no judgement), so marking fillets for rendering only (maybe as part of the gap definition) would be nice.