Hi Michael,
I noticed something strange when I save file after some transformations (extend, flow) with large number of objects.
File size blows up.
MoI Version 3.0 Beta Nov-19-2013

You can reproduce this.
Open test1.3dm (900 objects) -> select all -> Extend tool -> save as test2.3dm
test1.3dm - 0.6 MB
test2.3dm - 64 MB

Then select all lines, rotate it upside down (it takes a lot of time.. why?) then back. Save file again. ~2 MB.
I think MoI saves to file information about last transformation. Do we need it?
And another question. Is there any command which I can use in script to enable/disable undo, or clean all undo data?

P.S. Tired with 10000 objects :) igs - 7MB, 3dm -3.3GB(!!!) Please, fix it.