I have a full batman-adv mesh on openwrt routers. That's maybe what you are after? Full guide in the link https://cgomesu.com/blog/Mesh-networking-openwrt-batman/

How about netbird, all open source and self hostable

Also on Odysee (at least an alternative) https://odysee.com/@fireship:6/paying-for-software-is-stupid%E2%80%A6-10-free:5

Not much help right now, but looks like voyager has it on the road map. https://github.com/aeharding/voyager !voyagerapp@lemmy.world

Has anyone compared it against seaweedfs?

Would like to hear how it workes out for you if you decide to transfer all 800 GB

Can't see why not. Personally I'll be paying for them(ente) to host it for me to support development.

Logseq is pretty close