I don’t fully understand the fuss. When turning left there is no requirement to be x inches from the curb. What’s important is that the turn is made safely. This is determined by a) not hitting the curb (though there are circumstances when this is accepted on test) and b) not being too wide. “Too wide” is leaving enough room for another vehicle to come between you and the curb. The exception to this, particularly with an artic, is if you have to move out a considerable distance on the approach to the turn in order to complete it without hitting the curb.
Let’s not make like more difficult by introducing spurious rules that don’t exist in reality! “Tidy” driving comes with practice and experience and is not required to pass a test.
Without wishing to hijack the thread, can I also point out that this discussion never arises with a drawbar as the major feature of that type of combination is that they “follow” the prime mover.
Good luck all, Pete 