A few points on Windows vs. FC, file vs. block cache.
Windows caches both reads and writes at file level and somewhat at block level (trust me, your storage would be abysmally slow if NTFS did not have some block level cache for the MFT).
The good thing about file based write caching is that it can ONLY result in a loss of data for THAT file. Block based level cache can result in the MFT not being written and that can cause more issues.
Also the reason Windows uses file based caching are certain memory mapping features which would not work otherwise securely.

I would presume FC will have an associated file system filter which would handle file level caching in case the volume is cached. A lot can be done at that level to make the most of available memory and not have double caches.