I figured it out! Now users of my instance can also get a free peertube profile at video.coales.co just by clicking the "sign in with coales.co Mastodon Instance" button instead of a separate username and password! That means I'm also at @msh now and my other users can set up too!
Gotta say though the "peertube-plugin-auth-oauth2-mastodon" has pretty useless documentation and has some jankiness to it--it forces the email address to be your Masto "handle @ instance" which seems wrong...
There is also another auth plugin that is just oauth2 not Masto specific (which the one I picked was forked from)...I'll have to dig into it to see why the fork was done.
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