It works, but there should be an option to only allow it in specific domains.

Does not work how I want/need it to. I just want a redirect from https://www.youtube.com/feed/subscriptions or /subscriptions?flow=1 to ?flow=2 which can work the first time but clicking other menus makes the app get stuck in redirect loop a few times before settling down back on the subs page.

Probably YouTube's fault because all they ever do nowadays is make changes that piss people off or break certain aspects of their platform.