Hi NS
I've just had a look at the STARS and it would seem that the route after LANAK is at the controllers discretion. The route that is currently used results in one less heading change and will be slightly more direct than keeping the traffic in class D.
From a totally selfish point of view (sorry xrayalpha) I would have no problem with the corridor being class D or TMZ except that it is sometimes difficult to get a word in. Now if Scottish Info could give a clearance....
DO.