five minutes to reconnect when a device changes network

This thread is nothing todo with your issue. Please do not piggy back on a random thread and start a new one if you have some problems.

no, i think this matters, especially for the laptop using vpn. After I finished a doc and want to sync to remote server, the vpn disconnected. Then I must wait 5 minutes to re connect to the remote server, then close the laptop lid.

Why not accept the new connection and drop the old connection? By the way, BtSync have not such dealys.

You can also click pause / resume in the GUI. As an alternative to waiting, that is.