You are correct that a reboot will trigger a full rescan. I’m always on the lookout for better sync. I just don’t think it’s out there right now for easy bidirectional sync.

Basically, if you want to set and forget, Syncthing is the best option. If you want more control, you’ll need to look into setting up rsync scripts or similar, which will at least better let you control how often to sync.

I like async but dislike await. I spend entirely too much time on everything I build trying to maximize how much I can do in parallel because I find it tremendously satisfying.

In theory I guess it provides better security in some ways, but certainly not all over giving you hardware and a VPN. So there’s that. But yeah, it sucks.