It is possible to package a build without using pak, so the final build would be similar to your uproject build, where its just a bunch of uassets. I didn’t try to replace them with other uassets that aren’t cooked. like straight form another project. No idea if that would work. It would be neat that it works, but I think it will not work, as it would be a non cooked uasset and the game would recognize it. Would be worth a try though.
If this does work, it wouldn’t help my game much, as I would have to add 100’s of empty songs for modders to replace them. But for replacing guns, sounds, texture, it would be neat.