Federated sharing between two local Nextclouds, both with self signed certs

I remember reading at one point that federation between local nextcloud instilations with a self signed cert is not supported. Has this changed?

I can use syncthing or ssh or the nextcloud desktop and vdirsyncer to do some sharing stuff between the two servers but for things like nextcloud talk or deck it would be great if I could just use federation. right now every time I try i get errors, even through the servers supposedly trust each other