Yeah, it's a wrong warp of what ExclamationMarkYT said, it's due to being able to still move around in the file select screen and selecting another save while the loading screen is up. So when selecting a new save, try not to move up/down while the loading screen is up.

Yeah, apparently in both Legacy & V1.1, you can still move around the file select screen while the loading screen is up, thus making you wrong warp to different Isles instead of starting in Isle 1.

No, it's not allowed (Anything glitch related is banned in Hater%).

There is another way. If your PC has Bluetooth compatibility and so does your controller, you can connect your controller via Bluetooth and assign player 1 with the controller connected to Bluetooth first, and then you can connect your controller via USB to trick the game that you're using 2 controllers and control both players.

(I was able to do this with my PS4 Controller and it does work and it should work for other controllers as well that has Bluetooth compatibility).

What does "Ban Legacy" mean for One Gun?