Here’s a bit more about #syncthing
I have regular files I sync across machines, but they don't change much.
My "interesting" use case is an app I've been building for tasks and reminders. Each one is stored in an individual file that syncthing coordinates.
On my #librem5 #dogwood that has actually been working really well so far over mobile data and wi-fi. Changes have been flowing to and from the L5 without trouble and when expected.
They are tiny files. Less than ½KB each. ~32KB total.