If you do need that insurance rider for the site owner and this is not your listed site for your ama chartered club then you will need to run an event sanction for the dates of that event and will need a contest director. It makes no diff if its a competive or non competitive event.

An already existing rider for your clubs main site owner will not apply to another site owner unless you run a sanction for the event and obtain the sanction and additional rider.

John