Actually, the bug report confused me.
I would expect the GAIN knob to increase the difference between input and output audio (which is gain as opposed to volume). I would not expect it to have any meaning for MIDI.
Isn't that how it works now?
EDIT: OK, I think the OP is saying the same thing I say above: it's just that the bug report is confusing to me. Maybe Cakewalk misunderstood. In any case, this doesn't bother me.