Vacating expeditiously
I suggest you reroute your query to the ATC Issues forum, it is further down the page. I'll bet you'll receive loads of comments there.
As a long retired LHR/EGLL Tower ATCO I hesitate to get too involved myself but it was something that constantly exercised our minds and, those of us with pilot mates (in my case, dozens with loads of airlines - a legacy of my Hercules navigator time) were always trying to push this.
Most pilots did not realise that airfield slots and runway capacity were decided by the users and BAA ( the operators) with only a small input from ATC.