I just started watching a couple weeks ago and I’m still new to Mastodon. Anyway, what I do is:

on a laptop, open two browser windows, side by side

• One to https://mastodon.social/tags/monsterdon which automatically updates to the most recent post that people make on Mastodon using the “monsterdon” hashtag
• The other to the movie; usually https://miru.miyaku.media/ but once I did youtube

Another possibility: I’m thinking of putting a Mastodon client on my phone and watching the comments on the phone while I watch the video on a laptop or TV; I’ve done something similar for sports games and Eurovision.

I guess I could do it all on the phone, with a “split screen” and Mastodon on one half of the screen and the video on the other half.