I would really love it if Collisions between objects in your hand cursor were disabled.

Currently, when you grab multiple objects by right-clicking while holding an object those objects will collide with each other. This is usually fine, but it tends to become a problem when there are either too many objects that you're holding or objects with shapes that are too different. The objects start glitching out, moving around and making noise, sometimes just having weird behavior, and usually rotating them at an angle that makes them not properly drop-able (they'll have rotated on their side or upside-down).

This is a pretty big problem, to be honest. It feels really bad and it means that you have to interact with a few objects, deal with them, then move on to the next one, when you really should be able to do it all in one go. So, to fix it, I recommend disabling the collisions between all the objects that you're holding. They would still interact with everything else (what's on the table, etc), but just not between each other.

I don't know much about collisions, but I think you could create a "collision group" when you have objects in your hand and have objects from that collision group not collide. If so, this should be relatively easy to implement, and it would really make the very crucial interaction of "picking stuff up" feel much much better, responsive, and less buggy.