I was able to mount the PIMORONI NVME Base under the iUniker Pi5 case. I had to do a slight widening of the SD card hole in the case so the cable would fit more easily with less stress. It was a very tight fit without the modification and was pulling the cable out of the socket on the base. So far I have had no issues with the base and really like it. I was able to get up and running with zero errors with the supplied Netac SSD and a Crucial P5 Plus 500GB SSD that I had lying around. I have since repaired the scratches from my dremel tool with a black sharpie.
The Amazon link for the case is: Amazon.com: iUniker Metal Case for Raspbery Pi 5, Pi 5 Case with Pi 5 Active Cooler Support VESA Mount Fit for Raspberry Pi 5 (Official Pi 5 Active Cooler) : Electronics