@simon If you go the federated route, I like how these daily prompts work. See ,https://kmcd.dev/posts/daily-prompts/ for details and then click on the /prompts section to see them in action. (there is pretty low engagement)
That said, I saw your post about using GitHub Auth and that's what I default to these days. The stakes are higher for not being a jerk plus you have GH's moderations rules/team should you need to have to report someone.