M.2 shows up in BIOS but not in boot list

Do you get an "Access Denied" message? I get that as well. Couldn't find a way around it.
Posts I've found online say to format the boot partition but that didn't help for me.

You've come to the same conclusion I have: just get a regular SSD drive...I've seen benchmarks putting SSD ahead of NVME in booting times.

This sounds like what happened to me.
In your UEFI boot list there should be a "Microsoft Windows" entry. If it's not there, you have to create one manually. This is done from Windows. The tool to use is called "bcdboot". When you run bcdboot c:\Windows, Windows creates a boot entry in your UEFI.

In short you boot your system using a USB stick with the Windows installation media on it. You go to "Repair" and open a command prompt.
Next, you have to mount the partition that has your EFI software on it. Windows creates a separate FAT32 partition just for this. Use diskpart to mount it and give it a drive letter.

Then, you run bcdboot c:\windows. This will create the necessary UEFI boot entry for you so you can boot normally.

Whoever invented this and figured the old way of just setting a partition to "Active" wasn't cool enough should be shot.

Anyway, for full and detailed instruction look around for "bcdboot" instructions on Google.