[g_p]

One convenient feature if you run a third instance on a server is that you can "distrust" the server by encrypting the files you sync (this is done at share level), then only entering the decryption password on the trusted end devices. That way plaintext file content doesn't sit on the server.

It's worth checking exactly what is encrypted as I don't think folder and file structure and names were encrypted.

[martinbaun]

that's superb cool!

Can you tell me what this feature is called?

[wadim]

https://docs.syncthing.net/users/untrusted.html

It's a setting you can find in the advanced tab of devices.