That fixed the HW errors. They are now 0 after running for about 10 minutes. I also backed the throttle down to 225MHz. I have a little USB fan cooling the devices but right after I posted my first reply I got a seg fault that crashed Raspbian and had to hard reboot it ('reboot' command wouldn't actually reboot it, it would just hang). I am not sure if they are related but since I had the devices hashing all night @ 100MHz without issue it seems too coincidental to not be the cause. I'll keep an eye on it for sure.

I definitely don't have 20 year old eyes anymore but it looks like the dial on the pot has two flat sides. Are you saying I should turn it nearly half way? Clock or counter clock-wise? Is there a way to check what the actual wattage being pulled is (like in the USB management)? I didn't see it on a cursory glance but maybe its something that can be calculated?

Thanks for the support guys!