How can I make my UCanDo roll faster at slow speed?

I feel like the loop rate is much faster than the roll rate when slow and I want to be able to zip it round quickly. I've tried up to max travel on ailerons, I guess the servo wouldn't stall out at the speed even so I have 9402's.

Can I fit bigger ailerons or add tips or something or maybe differential to take
some drag out, I'm 90 degrees equal travel all over.

Mel.