there are custom Gamepad firmwares?No, because the gamepad starts up well before the earliest currently available avenue to run custom code (CBHC)
Drill a hole in the battery compartment and put a switch in series with the battery, will also be update proof
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It might be possible by developing and flashing a custom gamepad firmware that ignores the remote power up event, but good luck finding anyone who understand its firmware AND is interested...
There's also "Padcon" which allows for 1-click backlight switching, but nothing automatic at all
Not that I know of, although the tools to extract, rebuild, and flash the gamepad's firmware exist!there are custom Gamepad firmwares?
Technically it works but it's kinda outdated and not very user friendly. [It's pretty advanced]Not that I know of, although the tools to extract, rebuild, and flash the gamepad's firmware exist!
You can use CBHC Mod by @panther666 to autoboot PadCon. With PadCon you can disable the Gamepad Screen while still being able to use it as Input device. That's what I use and love it, always have the Screen turned off