As someone who has performed data recovery on optane systems. No, just no.

There's larger slow mechanical storage.

Faster flash and xpoint storage

RAM.

Any device can use a level up to cache and appear faster.

But RAM caching is generally better handled by the OS itself.

Flash coaching isn't an awful idea except when it goes wrong your back to "safety remove disk" being absolutely vital. So the OS needs to be aware and cutting power at the wrong time can kill your install.

Every update says "so not turn off your computer" for a reason but the actual redundancy we now have is leagues better than 10 years ago

God forbid one component in an optane chain becomes unreliable.

Ultimately everything needs to run in RAM. Everything needs persistent storage. A non-standard middle step between persistent and volatile memory is best avoided.

Xpoint was an interesting experiment but CXL replaced it. Ultimately the choice for data centres is to support more RAM. The additional RAM replacing the optane cache while the waits to be written is more compatible and predictable.

You can now have terrabytes of RAM and if you rarely boot and have redundant systems. There's need for the middle step.

The cost of memory and SSD per gigabyte as a cache matters. But RAM error correction and other protocols give even more advantages to avoiding optane.