Personally I would like to see a blanket ban during practices and races. For every competent pilot there will be a thousand who are not. As a marshal I don't want to tell someone that it is dangerous because I think it is too windy when somebody else in another sector says it'll be ok if they keep it off the circuit etc . Having seen a model helicopter smash itself into a thousand pieces when it was caught by a gust of wind, picking up bits of carbon fibre, plastic and aluminium off the circuit during a race is too hazardous.
Dogsbody