Starting and stopping a stereo playback with the same softkey works.
Starting a stereo or multitrack record with a softkey works too, although you have to arm the recording first. But stopping the recording doesn’t work, neither stereo nor multitrack.
Seems like a source code copy&paste that wasn’t tested. It seems the “play/pause” part was copied from the stereo playback to the recording part, but there is no “pause” when recording.
Even after correcting this, the recording softkey function, as it is implemented at the moment, would be not so useful for recording since you have to first arm the recording in the corresponding screen for the softkey to be able to start it. Then (after this bug has been fixed in the next firmware release) you would stop the recording with the softkey and that would work too. But if you want to start the recording again, you have to go back to the Qu-Drive screen and arm the recording first. You can’t start a recording a second time by just using the softkey which would more practical.
Maybe A&H can fix this bug and let the stereo and multitrack stay armed if once armed, until they get disarmed by pressing the red recording button in the corresponding screen again. That way the softkey would work in a more useful manner (after the bugfix).