Impressive idea, but could it be simplified ?
Suppose we’re talking official and market place and FSX-converted aircraft. Asobo has all models already. The issue is in the unofficial livery texture, or missing texture as a result of version difference (see above)
What if a MP pilot could join a multiplayer flight… and upload some “avatar picture” or some country flag at that point ? When you join a flight, you need upload only that single picture, not the complete livery. Works like an avatar on forums. Others see standard livery, but with your avatar added to the tail of the aircraft ! And because that symbol is a single png or jpg, Asobo could scale it, convert it server side to DDS if needed… no validations or virus checks are needed, it’s one simple 2d image.