Installing the DCH driver caused a strange but repeatable bug. When rendering in/out, if you open a browser to cover Premiere's window or minimize Premiere, the CPU goes to 0 and Premiere freezes. In the Task manager trying to terminate manually gives a "can't terminate while exiting" error. Restarting the machine is the only workaround.
Another bug that crashes with these drivers was trying to encode an hour long 4k video. Nvidia encoder (AME) would crash at the same point. Disabling hardware based encoding allowed it to continue.
Installing a clean version of non-DCH drivers got things working again on my machine without any errors or crashes.