Update after 24 hours of this… Remote harvesters on NAS is 
awesome.
Response times are consistently less than 0.5 seconds and I haven’t seen a single response even hit 2 seconds. I don’t need to worry about network congestion, and copying files from USB doesn’t affect speed at all.
I bought codinghorror’s remaining NAS, and I’m going to shuck a bunch of drives and set them all up, within a week or so I should have 5 remote harvesters and 8 or 9 plotters. Still wish I could plot faster, but I really don’t have the time to hyper-optimize that. (at 661 plots now)