Would being able to edit the "Playback Range" field by hand be good enough? MC supports this functionality but doesn't expose it to the user. (it's how CUE support works for example)
This would be very interesting. Naturally there should be a way to keep the playback ranges that are edited by hand and the ranges coming from cue files separate. Perhaps you could make a second playback range field, which would display the selected range in a standard time format (like:
In 1:25 Out 3:94). MC could use the combined values of these two separate playback range fields in case the file happens to be a cue file.
Many video editor programs use the "i" and "o" keys for specifying the in and out points on the timeline. Something similar could be added to MC. For example: select the "playback range" mode - seek the start point and press "i" - seek the end point and press "o". And of course: press "c" for clearing the range.
MC would use this memorized range whenever the track is played and this function is enabled. The function could have an on/off button besides the Continuous and Shuffle buttons. The DSP button could be separated from this group of three buttons because it has quite different purpose.