about the 4th gamepad slot; i'm sort of surprised it's happening on linux, but that's how controllers appear on windows.
per the gms docs: https://manual.gamemaker.io/lts/en/GameMaker_Language/GML_Reference/Game_Input/G... (it's under the platform compatibility section)
- game maker detects the controllers in the slots as they are assigned by the OS, on windows 0-3 are xinput devices, and then 4-11 are direct input devices, typically filling in the first device detected into the first appropriate slot. blade sight doesn't have auto-detecting for the input slot set up, so that's why it needs to get manually selected