Never subscribed to the thinner handle/more control thing - better feel, ok if you prefer that, but more control? Doesn't make any sense to me. Rubber may not be solid, but whatever force you put into it must come out of the other side of it. I'd say I personally feel like I have more control and the bat is less likely to twist with more grips - more leverage from a thicker handle, plus the shock absorption from the rubber.
Don't understand why you think it's more likely to twist and lose control? Only thing I can think of is that you're maybe meaning the extra grip would lead to more flex? But that wouldn't lead to losing control, if anything because you have the extra thickness of rubber it could take a higher twisting force before causing you to lose grip, which is when you lose control. And if you can take more twisting force without losing grip, then your control over off-centre shots is logically better?
One thing I would say to anyone who's unsure about two grips - try it and have a good bat with it so you're used to it, then decide. I bet you never go back!