I think I might have found something.
I also have the following in our Bonanza_g36_interior.xml
XML:
<!-- ENGINE #####################################-->
<Component ID="ENGINE_Throttle_Levers">
<UseTemplate Name="ASOBO_ENGINE_Lever_Throttle_Template">
<ID>1</ID>
</UseTemplate>
<UseTemplate Name="ASOBO_ENGINE_Lever_Propeller_Template">
<ID>1</ID>
</UseTemplate>
<UseTemplate Name="ASOBO_ENGINE_Lever_CowlFlaps_Template">
<ID>1</ID>
<USE_TRAJECTORY_DRAG_MODE>True</USE_TRAJECTORY_DRAG_MODE>
</UseTemplate>
</Component>
If I comment out
<UseTemplate Name="ASOBO_ENGINE_Lever_Throttle_Template">
<ID>1</ID>
</UseTemplate>
The throttle does stop moving (completely and doesn't show input at all) but the affect works, kinda. It is pretty violent and eventually gets to the engine getting stuck running at 640rpm and no amount of throttle will do anything.
I must be missing something in the rest of our code perhaps?