Hello, I've registered for this feature also.
Currently, in my specific situation, anything other than native flushing is unusable here, as it refuses to flush while the CPU has some load, even when the SDD is idle. Whereas, I would like to have a more infinite deferred-write, and rely more on the different write modes to keep the buffer under control.
I would prefer to use CPU cycles to have the cache write when the SSD is idle, rather then the cache writing based on a defined time period, often while reads are happening.