Nex-5N Bug: Why can't I use DMF unless AF gets lock first?

My setup is this, P-mode, multiarea AF, DMF
With shallow DOF you often want to select the interesting focus point
on the touchscreen. If you or the camera miss adjust with DMF with magnification.

My problem is that if the camera don't lock focus when you first touch
select an area and halfpress, the DMF will be unavailable.

Turning the focus ring does nothing unless the focus area is green and locked...

Any workaround?

Focusing somewhere else and moving back and then DMF would work.

Not using touch focus takes the AF-magnification to a random point and is useless.

AF-assist is also buggy and unavailable in DMF mode, it should have enabled MF.

Manually enabling MF is multiple presses and out of the question since you
first compose and get ready to shoot an image when you need to fine-adjust focus
it will also loose your touch-focus selection where you wanted to focus in the first place.