Hello everyone! I’ve read through a bunch of threads here on multi-site Discourses, but noticed that most of them are from 3+ years ago so I wanted to check in on whether there might be any recent advice, changes, tips, or war stories to be shared of managing a multi-subdomain Discourse community.
The problem I think I’m trying to solve is: I have a domain, and on this domain I’d like to create potentially thousands of subdomains, each focused on a niche (and mostly distinct) topic. I’m also considering an option that will involve only hundreds of subdomains, and that’s really the lower bound; each sub-community really shouldn’t have to filter out any other sub-community’s posts/people/messages.
Ideally, I’d like for auth to be shareable across each of these subdomain instances, but it’s not necessarily critical. Similar to reddit, in the sense that there is a global account but also per-community flair you can get, I’d like to establish a central identity with the ability to express that identity only through specific sub-domains as desired.
With all of the above in mind, I’m about to dive down the rabbit hole of documentation starting from Recommended Hosting Providers for Self Hosters and then diving in to Multisite configuration with Docker. My worry is that the latter article is from 10 years ago and miiiiight be out of date 
If there’s any advice, warnings, or general offerings of insight, I’m all ears!