Since Apple is deprecating kexts from future OS releases, I've taken the liberty of building a DriverKit-based solution that enables using Gamecube controller adapters in Big Sur onwards (so presumably, it should work in Monterey as well - but I haven't tested it in any betas yet). I also have a kext installer for Catalina/Big Sur/High Sierra.
The project can be found here: https://secretkeys.io/gcadapterdriver/
For Big Sur users, you'll want to run the app, then look in your taskbar. It should have an icon you can hit to reveal a dropdown, where there's a toggle to activate the driver. It's a bit finnicky but should be much easier than dealing with Recovery Mode.
Catalina/Mojave/High Sierra users, you'll want to just run the installer package. Anything older... you can go the old school SmashEnabler route, I suppose.
Both of these apps/installers should be fine as-is and do not require disabling SIP.
The Slippi community has been using these for the past year in various forms and they're relatively solid, but it's open source and I welcome bug reports at the git repo: https://github.com/secretkeysio/gcadapterdriver
Side note: the page notes this but worth pointing here due to the years on this thread - you'll want to remove any older adapter drivers before using these.
The project can be found here: https://secretkeys.io/gcadapterdriver/
For Big Sur users, you'll want to run the app, then look in your taskbar. It should have an icon you can hit to reveal a dropdown, where there's a toggle to activate the driver. It's a bit finnicky but should be much easier than dealing with Recovery Mode.
Catalina/Mojave/High Sierra users, you'll want to just run the installer package. Anything older... you can go the old school SmashEnabler route, I suppose.
Both of these apps/installers should be fine as-is and do not require disabling SIP.
The Slippi community has been using these for the past year in various forms and they're relatively solid, but it's open source and I welcome bug reports at the git repo: https://github.com/secretkeysio/gcadapterdriver
Side note: the page notes this but worth pointing here due to the years on this thread - you'll want to remove any older adapter drivers before using these.