U2F/FIDO support for Authentication
I understand Twitch has recently allowed people to use other apps for means of authentication, but please allow users to use U2F/FIDO authentication, this is not only more secure but also very reliable. Having a U2F as primary with a TOTP as a backup is in my opinion the best method of security, given that Affiliate/Partner accounts hold alot of personal Tax information, I feel this fits more as it's such sensitive information.
Supporting multiple U2F/FIDO devices instead of just one should be a requirement if this was implemented. Having the option to use backup keys is something missing from a lot of sites.