reason for not having dynamic control during playback is that the HDD is mounted read only. imagine if you were doing a change, you would first need to turn off the current song because you need no files to be in use when you remount. secondly, if you accidentally reset the unit while its writable.... 60 minute fsck awaits you.

now if all those functions were stored on the scratch partition, then it would make sense. sometimes you might lose information because it didnt write before you turned the unit off, but a lot safer.