@jeremyckahn I've been running my single-user instance for a couple it weeks. Storage is everything, not so much CPU or RAM. It fills up fast.
So for multiple users I would expect you have to add extra "object storage". AWS S3 usually being the cheapest, we're talking $1 for several dozen GBs, it's not so bad. VPS providers also have these.
I would not recommend having the instance open for all without a Patreon model or similar.