So please don't think surveying a runway gives you the 'picture'.
Sorry I should have been a little clearer, on days where you can hear and see traffic on 07R I completely understand, my one example was actually no A/C getting airborne (TCAS) and one CX 777 taxing down J with no one at the hold when we were on final for 07L (gin clear day) we were taxing down V when the 777 got airborne ahead of us. This was what we thought was a slick opportunity do slot us in on 07R having requested it earlier. However you have explained that ad hoc changes aren't the best. I guess what myself and others are looking at is efficient practices used at other airfields and if they can be applied to HK, likewise I look at some airfields and think why don't they do it like HK ATC.
All info much appreciated. Cheers