I used to do this. I finally had to switch off of it because the Syncthing Android experience is so bad (necessarily, because Android is bad).

I had many instances of not noticing Android had killed the Syncthing backend again despite being explicitly told not to, and then I had two out-of-sync password databases and would have to go merge them again.

I'm still bitter about it, because Syncthing as a syncing layer is so much more elegant than everyone implementing their own server and sync protocol.