For anyone that cares, I have a 3-part series on my website called HHDD (Homemade Hybrid Disk Drives).
It documents what I've done with a product called PrimoCache. The flexible configuration of PrimoCache allows an allocation of spare RAM (I have 48GB, used about 18GB for PrimoCache) to speed up read and write operations to drives of interest. Think of it as Optane assist implemented in RAM.
I found it to be fun and effective, but since the two critical-for-speed media drives in my system are RAID-0 SSD and RAID-5 HDD, the difference was much more apparent during benchmarks than it is/was during day-to-day usage. While ATTO Disk Benchmark reports about 11,000 MBytes/sec (yes, 11GB/sec) for read/write, the AJA benchmark tops out at a a lowly 2800 Mbytes/sec or so for read/write. In either case, the machine is snappy enough no matter what, and ... I've found no real benefit for CbB usage with PrimoCache engaged.