"Throttle Hold" for RC boat or car

The Futaba T8 has a "smart" throttle hold option, meaning: The throttle hold will only engage when the throttle stick is close to the low position. Makes sense for an airplane or helicopter that uses a range of idle-to-full throttle. Does not help with a car or boat where you want reverse/stop/forward.

For a boat I wanted the throttle hold to hold the throttle output at 50%, but the built-in throttle hold function would only engage after moving the throttle stick near the full reverse position.

Fix: Use throttle curves.
Curve 1: usual 0..100% linear curve.
Curve 2: Always at 50%, with switch "SF" to engage, the same one I otherwise use for throttle hold.