Unfortunately this wouldn't work like that - we've always planned to add a "mark for deletion on next sync" flag which can be set during playback, but the fids partition is kept read-only the whole time the player is running and so we can't write to the *1 files.

The dynamic data partition (hda3) is designed for this sort of thing, and its contents can be accessed via the protocol - this will be further documented when we've got the dynamic data stuff slightly more concrete (ie: it changed a couple of days ago!)

hugo