I am VP of the local public gun club and the Pres. of the competition sub-club.
You're required to go cold when you enter the area designated to hold the match, and we have that area well defined.
As far as spectators go I adhere to "don't ask, don't tell". If your gun inadvertently shows you go cold or leave. If for some reason you out yourself in a stupid fashion (ie: pull it out to coon finger it) you are told the leave and not come back.
As far as RO or competitors carrying hot hide out guns, "don't ask, don't tell" under penalty of DQ.
If you do something totally moronic with your hot gun you'll be told to never come back.
The public access ranges outside of the competition area are just that, outside of the competition area.
I'd have to laugh at someone who thought we had the authority to disarm everyone on the range because our shooting match was being held on a portion of it.