Is it possible to use multiple TCP connections to speed up sync between 2 hosts? I have tried increasing pullers and copiers on a folder, but sockstat/netstat shows only 1 TCP connection used between hosts.
Using iperf3 with 15 parallel TCP connections I can hit ~25Mbyte/s. Syncthing is topping out around 3MiB/s.
Syncthing will only ever use one connection between two devices/nodes.
You could run another Syncthing instance on one of your devices, but to not mess things up, you would have to place the same Syncthing folder in another directory, so the two Syncthings won’t interfere with each other.
I do that to give my Wifi sync to my phone more speed.