On my machine there was an 1TB SSD configured as a SRT array member hosting OS volume (868GB) and a cache volume (64GB). The cache volume was accelerating a secondary HDD GPT-Partitioned NTFS-formatted.
After a BSOD the secondary HDD become inaccessible (RAW, no partitions at all). I was able to recover some partitioning structure with Partition Recovery, but many files are lost, apparently the most recently used.
So I suspect a problem with the cache volume.
I now disabled the cache on the secondary to prevent any overwriting, but the SSD still has an unused cache volume.
My idea was to delete the cache volume and recreate a regular volume on that 64GB, and try a deep scan of that volume with Active File Recovery ore Recuva.
The problem is I'm unable to "reset as available" the cache volume. The UI of ISRT has a button for this but has no effect.
When you use only a portion of a SSD to cache a HDD, what Intel RST does is create a RAID array that includes only the (single) SSD drive. It then creates two volumes in this array, one for the "data" volume (your boot partition) and one for the "cache" volume. Now, in order to remove the cache attribute from this volume, I believe that you need to use the capabilities provided in the Intel RST BIOS extension. Reboot your PC and, during BIOS POST, use the CTRL-I sequence to invoke this extension.
As for process, if the goal is to try and recover more files via what's in the cache volume, I am not sure you will get much - but it is worth the try nonetheless.
Hope this helps,