Why spoof the game version? Just block System Updates, that should block all updates. Then just never update the game, it should let you play. But it will ask you to update every time you try to launch the game.
But if you never installed the update, then it should let you play just fine.
My BOTW is still on v1.3.0. But it's because I want to play with the Trainer, and the trainer has yet to be updated to work with v1.3.1.