I'd say AKA Handlebar STD are more of a match for the other bar type tyres. But on the topic itself, I see some issues.

1. One companies 'soft' may be another's 'medium' etc. Therefore, you have to keep it open compound, thus increasing the number of compounds you have to take to an event.

2. Then, other than sponsored drivers who are locked into a particular brand, you will end up with people taking multiple brands of tyre to have the right one as one companies bar tyre may be slightly different and better to another.

3. Diluting the number of 'sales' for the event tyre supplier by opening it up to multiple manufacturers will make it not worth their while. I'm not sure what the margins are, but they make little on a $15 control tyre now compared to retail. So if they don't get sole bulk supply for an event what is the incentive for them to supply them at reduced prices.

4. This would only be an advantage for sponsored drivers as they'll get to use their own discounted tyres and will save them a lot of money, but for everyone else it'll add much more expense to a big event. Plus you'll have your 'top 5' in the A Main able to afford to throw new tyres on every run, whilst the other bottom 5 will have to pay a premium to do the same.

I think you either need a single control tyre and compound or else you may as well go open tyres.