What about having a method to add a new scope to an existing token? Twitch already has the list of approved scopes, so that’s not needed. Just add the new scope, generate new token, profit.
That way, the user isn’t bombarded by having to re-auth every scope that they have already approved. The screen would just show the new scope that’s being approved.
The big issue with this for me, aside from having to nag and annoy users to re-auth, is that the auth page UI is … umm … quite bad. The UX rates 0 out of 10 for me. Design is not my thing, but I’m sure there are some designers and UX specialists that could make some major improvements there if Twitch put the resources on it. 