We’ve started designing a PCIe card last week, an adapter from M.2 E-key to E-key, that adds an extra link to the E-key slot it carries – useful for fully utilizing a few rare but fancy E-key ...
2 M-key sockets specifically for that, and there’s NVMe support in the RPi firmware to boot. Plus, you can always plug a full-sized PCIe adapter or an extender into such a socket and connect a ...
2 to M.2 adapter for quite cheap, it's almost tempting to try it out. Alas, PCIe 5.0 adapters are hard to come by, so you'd have to nerf the drive down to 4.0 speeds when you drop it in your rig.