It depends on load I guess.....I know when my car was stock it was not a huge issue going across the gate all the time but I never stayed there more than a couple of minutes. But... with a little bit of HP/NM the standard GB cooks pretty quickly(better once the HD2 kit is done)........a couple of minutes wont hurt though imo......best idea is to knock it across the gate after the second gear shift.......with the standard turbo revving the thing to 6,500rpm is a waist anyway + your already doing over 110km's.
Mind you Paul you will find after you do a couple of the VB's a difference in oil colour between those who drive across the gate all the time and those that don't.