Servo Mount retract servo-no movement

Im finding it a bit confusing trying to figure out how to setup a servo to extend/retract a gimbal, not just from a TX switch.
Most of the documentation refers to landing gear and I not sure just reversing a servo that would otherwise operate landing gear, will produce correct results.
Having just setup a gripper, this has separate end limits for the servo. I would expect something similar for a gimbal retract but there is none. I guess just use the standard servo min/max settings. Could the servo speed be adjusted?
Also in missions, there is no mount retract, just yaw,pitch,roll settings. (do extra parameters appear if LGR is enabled?)
In the case of radio failsafe and auto landing, will the mount retract?

Any advice appreciated thanks.

Why is there no mount servo movement?

I have set radio CH8 to 27 which is ‘retract mount 1’
When CH8 is operated there is a mavlink message RC8:Retractmount1
So far so good
I have a servo on output 7 and set to 9 - mount retract.
There is no output on servo7 when CH8 operated, even when armed.
It DOES work if servo7 is set to 58, RCin8

Any ideas please?

So, I have figured out that the gimbal can be extended by a ‘point camera here’ option and it is retracted by any action on the channel set to ‘27’.
Still need to know-
Is there a setting to make the gimbal retract in an RC failsafe situation?
Can I set the gimbal to auto retract at a lidar height?
If I have no groundstation, how do I extend the gimbal from RC?
Why, in mission planner actions tab, is there no drop down ‘set mount’ options.