Thanks for the reply @Dist. So I am to understand that there’s no way to really accomplish this through the oauth directly, but only from within the bot code itself. It looks like the authentication is a layer that just enables the bot to be added to the channel, and from there I need to deal with actually adding it to the channel via nodejs/bot code.
I was reading that people oftentimes have a !join command that people execute in their channel once the app is authenticated, or something similar, so I’ll look into that, or alternatively have a closed endpoint to get the bot to join via the oauth return url. as for getting the bot to rejoin I think sqlite should be fine for keeping track of the channels.