Does B550M pro4 support any M.2 NVME SSD£

The QVL list is just a suggested guideline, in other words it lists the M.2 SSD drives that have been tested and guaranteed to work however any M.2 SSD you buy should work absolutely fine.

Any m.2 nvme drive should work just fine. I am running 2 in my b550 pro4. Just remember that the top m.2 can run up to gen4?4, while the bottom m.2 can only run at gen3x2 speed. If the drive you are getting is gen3x2, which is the most common, use the top m.2 slot.

Because NVMe is a standardized communication protocol, as long as the device (m.2 drive) follows the standard then it will work with the motherboard. Even newer gen4 NVMe drives know how to talk on gen3 ports. It is nearly impossible for asrock to test every single combination on m.2 drive and very little would be gained from doing so.

Just for the sake of over explanation and being a nerd, NVMe is the communication protocol (like english is one type of language) and PCIe is the physical interface that carries the data from one part of the system to another.

I hope this helps clarify some things!