Hi Ed,
Yes you can uplink from your switch to a NAS, but it depends on your switch. I’ve got similar hardware to you (QNAP 879) and have been beating a similar path as you – to get more bandwidth – via link aggregation, balance -rr, etc – I even went as far as purchasing the 10G card for the QNAP and have been testing it.
But back to the switch. I’ve recently upgraded after a long search to Brocade ICX 6450-48 switches which have 2 10GbE SFP ports and 2 1GbE SFP ports. (the 2 1G ports can become 10G ports with a license upgrade – i.e, more money). You can use the 10G for uplinking to another exact model switch (and then manage the switches as 1 device via IP/GUI) or you can turn off trunking for this port and simply use it to connect to a 10G NIC – like the one in my QNAP.
I will update this thread with my findings.
And BTW, I have no affiliation with any company mentioned, I’m just a paying customer!
Best,
Nick