I could be mistaken, but I'm pretty sure they had drag-chains on the trailers at the Wisconsin Regional also. (Al correct me if I'm wrong)
The Thursday practice day was pretty cold outside, so the heaters were on (which meant we were all walking ESD guns). I don't remember hearing any issues from other teams about loosing coms/reseting except on the practice field where the trailers didn't have any drag chains and the driver station was connected through the Ethernet port to the robot. We lost comms any time we activated a large sheet of fabric in our hopper.
Not sure if the presence of drag chains and no ESD issues was a coinicidence, but it seemed like things actually ran pretty smoothly once we got out on the competition field!