I would say to closely monitor and potentially adjust the OC. My rig would run fine for a while until eventually crashing within hours/days. Finally adjusted down the OC to gain stability and had some better success. In my opinion the coins lost during downtime more than make up for incremental OC that pushes your system to unstable speeds.
It is not OC because I tested with the default OC and the error continued.
I use 3 GPU Asus 570 4GB. Strangely the GPU2 presented the error and time after only the GPU3.
I have no idea what the actual problems are, but connecting the GPU directly on the motherboard solved the problem so far. I'm still monitoring, and if the problem continues, I'll try to switch motherboards for new tests.