There's a tag - podcast:socialInteract - specifically for this in podcasting 2.0. We've been looking at activitypub, but if Nostr is a better way to go (and I'm not convinced it is) then worthwhile chiming into the discussions.

Fountain achieves public comments with a 1% value split for all zaps ("boosts") received. Seems another way round it, and has the benefit of opt-in by creators.