In almost all cases, after a wake up all network connection have to be reset.
Also, Syncthing cannot be sure that nothing has changed inside the folder, as it only knows “I was frozen for … minutes” (it detects that all of the sudden, the clock jumped).
That (and maybe something else I don’t think of currently) is why the cleanest solution is to just restart.
In the current version, there should be no real disadvantage (I think). You should try if Syncthing still works after a long sleep without this setting.