I recently received the Pineberry Pi SSD HATs.? I have mounted the top HAT on my RPI5 with a Samsung 256GB 2042 NVMe SSD.
Following PineberryPis instructions I made the NVMe drive recognizable by the OS (/boot/config.txt) and modified the EEPROM boot order to boot from the SSD.
I used the Raspian DiskImager software to copy my SD Card to the SSD.
It all was painless and now my RPI5 boots from the SSD with Raspian Bookworm.
The difficult part was finding / modifying a case to put it in - I used a Geekworm case and broke off a segment to allow the SSD HAT standoff to mount to the RPI behind the USB sockets.
The HAT is a well designed great product.
Merry Christmas to all.
Edd - KD5M