This looks very cool and I could use it but I would be more happy for an EU version of this where I can simply pay you for hosting it for me, at least until I know my app or project is successful. I think there is a room for a Plausible version of auth. I think it's good that you offer to self-host it but honestly that is a bit of work as well.

I use a js-only backend so installing Java as a dependency maybe isn't the biggst deal but it's still something I will have to consider.

Even if it's more work to configure and setup an auth myself I will know the intimate details of how it works and don't have to spend time learning another tool in another language. Both takes time and since I've implemented auth several times already it isn't that big of a deal for me.