Toggle Pointer (Mouse) Scrolling by changing System Prefs

I would like to turn off pointer scrolling using a macro to interact with System Preference -> Accessibility -> Pointer Control -> Mouse Options -> Scrolling. I have found trying to get down to this level very difficult via Keyboard Maestro - even with checks and pauses, it seems impossible to get a consistent response from the UI - most times, the pane i want to pop up doesn't.

I've tried using command line control of 'defaults write com.apple.driver.AppleBluetoothMultitouch.mouse MouseVerticalScroll -bool NO', but that doesn't seem to take.

Any ideas?