When I did the Flying Supervisors' Course, they made a big issue of the number of accidents/incidents when pilots were 'showing off' to the camera.
So perhaps it's best not to advertise your presence by wearing a road-digger's yellow coat or whatever - just in case some fun detector should say "Hmm, don't like the idea of the chaps posing for snappers - someone might go a little too low or do something silly. Best we stop this sort of thing....."
I would suggest you just lurk in the weeds with your cameras - and don't tell people when you're there.
Excellent photos, by the way!