Other than agreeing with @batwood14, I think you could make it productive by seeing if it could substitute for something like Pettit. My experience with spin classes a thousand years ago is that you can basically cheat. Go as hard or easy as you want even when everybody else is jumping around like crazy. (Hate those pointless “jumps”).
You don’t have power, I’m assuming, so you could use HR and RPE to get a decent 45-60 min endurance spin.
I really wouldn’t try to do their “intervals”.