Right now I'm trying to figure out a highly-scalable flow of managing encryption (thinking of a hub with 10 million member as a random high benchmark example), for non-public hubs, so that a hub creator/admins can manage member whitelist and who'd be able to decrypt messages.

I think I'm close to figuring it out, but we'll see (hopefully i can, otherwise it'll just be a public solution only for release x3)

Once that is done / that hurdle is passed, then it's a matter of figuring out how to apply that for roles and channel-specific access.