Hi pafurijaz, both groups and blocks are poorly implemented in Rhino with a lot of problem areas. So even when these are implemented in MoI it's pretty likely that they will be custom implemented for MoI and won't be stored in the .3dm file's regular structure.

With groups the problem is that it's just a kind of tag assigned to objects and groups aren't structured in a parent/child relationship.

With blocks the problem is it's a clone of an antique AutoCAD system that has weird rules about how layers work in combination with the blocks.

It might be that I can shoehorn MoI instances into a compatible system with blocks, I'm not sure about that yet. I'm pretty far along with groups though and I'm pretty sure that groups will not be stored as .3dm groups though since there isn't any way to represent a parent/child nesting with them.

- Michael