Can anyone help me set up my Visa with a split rudder?

My radio is a Futaba 12FG and I have the second rudder half set up on channel 7.

I've got the split rudder now set up using exponential on each rudder half with the trailing half hardly moving at first but eventually catching up at full deflection of the leading half. To me, this seems funky and I don't know if I trust it. It also screws up my ability to put expo in the leading half of the rudder.

Haven't flown it yet - just getting it ready. Is the split rudder really worth having? I fly Advanced and usually don't have much trouble with point or slow rolls which I understand is where the split rudder helps the most.

Thanks,
Bob W.