Not sure what you mean in your example - the inblunds through LAM are of course at 4000ft against the deps climbing to 3000ft. (PM if you want!)
When LHR is on Westerlies, they cannot come further EAST than the north-south line through LCY. We cannot be above 3000ft unrtil 3nm EAST of LCY and that line.
It is a shame that we have NEVER had any crews plugged in with us from the operators.
10 left hand downwind does occasionally happen - but there seem to be more and more aircraft!!
No idea why not SA of 10 - as you say it is reciprocal of 28 arrivals, and go-arounds can go straight ahead!
Noise abatement eh! (Though oddly when you are out of the MSA (1800ft)) we can turn you!