Actually, we can support up to 4096x4096 bitmaps for the skins of any plane.
Some of the planes have an optional maximum setting (C47A, for instance) allowing for a larger than default skin bitmap size.
We have discussed setting all the multi-engine planes to a maximum of 2048, and the B29 to 4096.
When we update a model, the texture layout WILL change. No way to avoid that and it is something we do not want to try and avoid as it allows us to use our new tools which help reduce problems with texture fitment.