I think some frontends support HORM by storing the last song in a file on a writeable partition. That's the only way it will work. Or they can support the commitfile API that will "write through" EWF, but it's only for files that will not change in size.
The thing is, you really need to unmount your writeable partitions when you hibernate with HORM. Otherwise the write cache of those partitions will be saved with that HORM state and be used every time you boot up. In time that can really screw up those partitions.