But the Lua scripts would be bound to the underlying game engine. I would all come down to whether or not a judge would see it as a derivative work.

Lua is MIT licensed. The point is that if you have a GPL game engine and use lua scripts to turn it into a full game then you also need to license the scripts as gpl if you want to distribute the game.

(As others pointed out , oif you are looking for a loophole, game assets might be a better way to go)

The examples in the FAQ imply that they consider separate binaries that share “complex” data structures to be parts of the same program, blurring the line for what counts as dynamic linking.