I like to toy around with the interstage part, like the fuel tank and the rest it's very flexible, and helps me design stuff around the engines whilst still letting me attach stuff to it underneath [unlike fairings].
However, I've been bugged by that one floor that the part has. I don't really have a whole lot more to add, it admittedly is more of a flavour thing, but some sort of option to make the interstage part truly hollow all the way through would be a big help to me in my rocket building.
@AtlantikWall45 What I want is the floor on the interstage part removed, so that it is hollow through-and-through. I could use that for decoration or functionality a good bit more than as it stands now, where the floor often gets in the way.