I have a new PI5 and am waiting for my Pimoroni NVME M.2 Base (ordered and expected mid to late Jan). I have a spare Crucial P5 Plus 500GB nvme m.2 ssd. As an interim I have it installed in a usb3 enclosure but it fails during intense disk activity (e.g. sudo apt upgrade) taking a maximum current of approx 0.7 amps (measured with a cheap USB monitor dongle). An external USB3 Integral 240GB SSD takes approx 0.2 amps and works fine.
This leads me to worry that the new Pimoroni NVME M.2 base will not be able to drive the Crucial P5 Plus with adequate current. What are the specs of your nvme base? ?