I'm interested in knowing more about this too as I like the database localised with my app server (no network RTT!) but I also like to have a standby for HA and not being paged with everything down.

How litestream handles master-master or promoting a slave and switching back later isn't clear to me.

The closest thing I could find on the parent commenters blog was this

https://joshkaramuth.com/blog/django-deployment/

But it doesn't go over multi-instance coordination