Food for thought-if the resulting Vortice drag is from the wingtip.In the case of upsweep the drag vector would be above the thrust line(possibly increasing lift)..downsweep would provide the converse result -increase in natural (nose down)slipstream effect from the wing(that the stabalizers job to correct)..
Havind said that, it's up to be out of the way of the ground handlers(Hitting them)
