PC767,
Would you not be able to do the same with airport standbys, as we do at LGW? We cover both long and short haul from an airport standby and specific standbys will start at specific times to ensure the long haul flights flights are covered.
Please don't take this as an "if we can do it, why can't you" dig. It's a genuine question as to whether this would be possible as I'm not too familiar with QRS. You have many more l/h routes than us, especially the long range ones, which may make it unworkable for LHR, hence my query.