As already suggested by some in Nexus forums, can you please do what Clipboard (Nexus mod id: 31090) does in your mod with the layers concept. Though your concept is broader but at least with object/group of object cloning, movement, rotation etc is much better handled with that mod. That mod features a lot more ways to select, place, name and manipulate stuff. It can also select anything select-able through the console. It has ~500 slots for them. It is extremely fast at it, placing over 200 objects in a second or two. The author had stopped work suddenly in July, and he may resume in the future or you may try contacting him for a collaboration. The mod is stuck with F4 v1.10.98. Please, at least do take a look over his work.