Not sure if this is relevant to the problem I've been having, but looks like I had a buggered LACP setup on my switch... I suppose that happened after a firmware update, donno, doesn't matter....
Just a guess, but having 4 "bonded" NICs out of sorts could cause all sorts of BS. I've fixed that so now the Synology's bonded LAN ports are properly configured on both ends.
Regarding earlier idea of active hours, here's another slant on this -
Does it maybe make sense to set the refresh interval as a per device (via device page over-ride of the default). Reason is ALL my devices are sync'd and I use the 'master' device only to play/pause... but I do have some RM's to turn on/off outside devices based on time of day. So a refresh for any device other than the 'master' is unnecessary, but I'd like to be able to push an "off" or "on" command to the others via RM... don't care how they are set, so a poll isn't necessary. maybe too unique a situation, that's ok, just throwing something out there that may squelch a lot of traffic.