Well, it "is until it isn't",,,,,,,If I think I have something, and it is not in the Skyhawk spares box,,,,,,,then every other box that it might be in is a "wrong box". And haha, we all know what searching in "wrong places" means,,,it means you can't skip any because that might be where it is. I do have a "seats box" and a few "weapons boxes" and etc,,,,,so the search isn't as bad as it could be.
I once sold a used model for about $5 plus shipping, the guy that bought it was a nice guy,,,,and emailed me to tell me that he had a full box of seats, weapons, wheels, masks, and decals for the model and asked "did you intend for this?". I got the aftermarket parts right out of everything after that so it wouldn't happen again. (and I let him keep the goodies, it wasn't his fault)
Storing the flat box art is not that hard,,,,,,and I agree that I wouldn't store empty boxes intact, space just costs too much these days. (plus, Anne might think they are part of the stash, reducing the number of kits I could still buy without fussing at me)
Rex