You technically can self host, but be prepared to tinker. A lot. The app is really not set up in its current state for people to do that.
That said, about a week in, I feel I have ironed out the quirks quite nicely, and it works pretty much without issues.
I'm documenting my findings in this discussion, I'm hoping this can serve as a good resource for other early adopters and the eventual docs.
https://feedback.fluxer.com/p/1037
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Comment by @mgabor3141