That is actually a really nice idea O.O I also hoard packaging for the ponies I debox although I tend to throw out the internal plastic - with boxes like that...hrm.
I have space issues and I still need to get down all my G1 MIP, catalogue them, and then work out the best way to store them. I don't have a ton of G4 ones but I've realised I have enough to be problematic with space. I don't want to debox these or part with them...and I still have some G3 which I feel the same way about :/ So anything that resolves space issues is good with me.
Right now I have some bubbled G1 cards inside my UK waterfall box but I wonder if I can do something more productive with that space....
When I go home, I really need to do something with this. Thanks for the great idea. It's got me thinking about how I can more practically use the packages I have. I already keep G1 MOC inside Jem boxes but there must be more I can do...