If you want 8 man gates for the Open Motos, that is do-able. If there is only 1 gate, and you want to force a main, that too is do-able.
You guys, the one’s organizing, and racing in the Open Series, should decide the rules; how many you have to do, how many there will be, what the pay-out (how many) will be, how much of the day’s entry fees to apply to the daily payout and how much to allot to the final pay-out, where you’re going to get any added money above and beyond entry fees, are you going to allow cruisers, mountain bikes, girls, etc.
The only stipulation is that the rider has to be 16 or over.