- Frame-like machines, and turtles, are a problem since they don't actually break or place blocks when they move. You could build a machine that sucks items from chests, move it into someone else's base, run it, and move it back out. Not sure if Forge can help this - maybe it could have a BlockMoveEvent?
For these specifically if blocks get a new tag through forge that identifies the player could there be a check for the blocks before moving forward? So if they belong to a player that didn't place the frame machine then it'll just refuse to work.