I am not familiar with the limitations of the L2's auto pilot.
What I cannot understand it why there would be a need to decouple the automatics in a non precision approach.
In the S92 as you are approaching MAP you will call "I have control" if you have sufficient visual cues whilst the PM monitors. At this point in 3Q, as it's called in the S92 (I believe 4 axis in EC products) you have IAS, NAV/Heading and ALT coupled. You simply beep trim the IAS to the minimum 55 knots and beep down on the collective in Alt. You remain fully coupled whilst the aircraft descends.
Yes you may land longer than if you decouple decelerate and descend manually, but so what.
I have seen many times pilots decoupling at MDH, then decoupling and in my opinion, descending and decelerating too aggressively. In marginal conditions is not a position you want to be in.
With the 92 in 09 Sumburgh you would be able to remain coupled at 55kts, the minimum for the Autopilot (IAS), coupled to the localiser (NAV/HDG) and beep trim the aircraft onto the runway using the coupled collective (ALT) if you wished.
Is it not possible to do something similar in the L2, if not why is it not SOP?