I have a notch at mid throttle/pitch stick. It really helps with stall turns and rolls. On the 9Z you open up the back, wade through the circuit boards until you find the ratchet metal spring part.
I unscrewed it, used a Xacto knive to make a light line in the plastic halfmoon disk the ratchet rides on. Then reinstall the ratchet and check if the line is in the correct spot. Then undo everything again and make a bigger notch. Make it bigger than you think because when you tense up in flight you can't feel a light notch.

Fritz