Fareastdriver, I managed to scrounge 3 trips in the back of 'Clementine', the Brawdy target-towing Meteor T7, whilst at TWU. Apart from watching my colleagues shooting at our flag, my overriding memory was of the odd light sequence during landing gear extension (preceded by a positive check of "Airbrakes IN") - and the nimble footwork of the chap in the front ensuring that the ball stayed in the middle!
Presumably the height loss involved in the 'phantom dive' needed to retract the airbrakes and recover to level flight was frequently greater than the height available? Particularly if both engines were at idle during the run in and break.
In the Hunter, selecting airbrake in and gear down at the same time with the idle thrust would put such a demand on the feeble hydraulics that the controls would revert to manual - which certainly got one's attention during a VRIAB!
At least in the Gnat it was physically impossible to select airbrake in and gear down together - it was the same system. 'Airbrake' was actually 50%-ish gear extension - a clever idea!