It's difficult to say why Porter fails when it does, every user's experience can be different. Have you tried reducing the inventories of these families' and individual sims' inventories and removing any "special" items from them? Have you tried running Porter only after a fresh startup of the game, not on a session that has already been running for a while? Can you use the mod at all on a different world or an even smaller collection of households like two or three as a test?
And yes, you could also do this the Traveler way. But if you don't want to travel back and forth between the two worlds seven times and keep restarting the game after each Change Hometown to bring everyone over and wish to use MasterController after the first household permanently switches homeworlds to bring everyone else in, note that the inactive ones will lose their money and all of their possessions in the process.