I do quite allot of work that requires irregular hole patterns, these require bolts or rivets, the repetition of parts it not high enough to justify setting up iMates.
I would like the ability to have a part or collection of a few parts (bolt assembly) that I can attach to another part with an insert mate and it will attach a copy of the part or parts to the hole.
This seems like a fairly simple thing but I think would save allot of time. I could then use these parts as the start of the various patterns.
E.g. Insert a rivet into a hole, the rivet is attached to a part and a new rivet is generated ready to be inserted with the same constraint and the same constraint feature selected.