My lighting circuits are a mixture of 1mm^2 and 1.5mm^2 T&E, so ignore the fatter cable and just worry about the thinner stuff. The worst case reference method in insulation is 10A, correct? Just talking about the switch cables, rather then the loop-in/out between roses, so only carrying load of individual light fittings rather than the whole of the downstairs lighting circuit (6A MCB). two back boxes on oppsite sides of a stud wall, with a bunch of 5 cables in total, can I assume grouping factors don't apply as all the cables will be carrying less than the 30% of maximum circuit current? I suppose even if grouping applies, then factor of 0.6 of 10A is still 6A.
So in short, is it OK to have about 6' of lighting switch cables enclosed in insulation?