I've always gone with the principle that if it's likely to cause heart failure on the flight deck then it does no harm to specify from where the aircraft will be lining up from eg 'via T1 line up and wait'. The landing ac will then know that they have passed said point and nothing to worry about.
If the ATCO was attempting to 'time it right' and departing ac was approaching the holding point and not likely to affect the landing ac when he issued the statement. I have but one comment.........slippery slope and all that!!!!
I am an ATCO at a unit where hi intensity runway ops rely on the use of conditionals (every 20secs on line up delay counts towards the next go-around) - anything we can do to retain their use we will do. If an LCE at our unit was to overhear the quoted EGLL example it would start with a quiet word in the shell like and move on up the scale of lessons in what not to do and why.
