>>So, there is a chance that writes don't make it to disk, but since most
normal programs in CP/M return to CP/M, the reading of the system
sectors should satisfy clearing out the cache.<<
CP/M bios get signals from the BDOS to determine that for deblocking.
The BIOS then only needs to do a "updated" read and the SD will write
its cache and get the requested block.
Warm-boot should do that as well and Cold-boot should as well as the
first thing is a read to login the current directory (usually A:).
That should apply both for CP/M deblocking and triggering a dirty
cache in the SD (its internal caching).
Allison
