When oversensitive cornering auto sensors apply the trailer brakes it feels momentarily like the sensation you get if an inside drive axle wheel has started to spin and TC/ASR has cut the power on a sharp corner, after its happened a few times and you realise cos dry road and say 40mph that no way was a loaded vehicle going to be spinning a drive wheel up like a powerful RWD car.
They are definately weight sensitive (or lean/yaw or both?) because it never triggers on mine when empty.
Incidentally if anyone knows exactly how these things operate it would be interesting to know.
Sounds like a decent days work there BoltonBoy, will you look for such work for full time?