Since we’re here to use Discourse on this particular free hosting, and I guess often to try Discourse as an admin and do various tests, I’d advise using their low specs servers instead of playing with new features that may have obscure limitations.
1 CPU, 1 GB RAM, 500 MB of bandwidth, and 100 GB HDD is enough for that kind of needs, or for a very small community that doesn’t care about a few seconds when opening a page.
For anyone that wants to use more robust solutions, regular hosting companies like Digital Ocean, Hetzner, etc… Will do it for cheap:
A personal note: on one of my free instances, I host a private, personal Discourse that I use to store various information regarding IT stuff -problems, solutions, tools, etc-, but also movies to watch, music links, books information, etc… It does its job perfectly, for free. I keep regular, external backups using rclone. So these low-specs VM can be used for this kind of stuff.
