Has anyone ever used the double thumb layout ? How did you like it ?

I really like it on something that is skid flip to get it to read the mids a little better......not so much on earlier rolling balls.

I'm thinking of using it on a Radical Cash. Looking for maximum hook.

For a THS or sport shots?  As someone once told me, it's not about total hook but where that hook happens on the lane....

If you're committed to going this route for max hook, my suggestion is to lay it out for a double thumb without the balance hole first.  Take it out to the lanes a couple times to practice to figure out if the double thumb balance hole makes sense or if a weaker placed balance hole makes more sense.  That way you give yourself an out if the ball is too strong for your intentions.