Re: 2.10 EarthManipulator::OPTION_CONTINUOUS zooming doesn't work
I tried this on 2.10 branch with different results: the KEY_Minus operation works, but I had to add a SHIFT modifier for the KEY_Plus to work. (That is a separate bug.)
Key-based actions do not use the CONTINUOUS option. It is only used for mouse dragging actions. The continuous behavior with a key-based action is just the system sending key events as you hold down the key. Using the CONTINUOUS option for keys might make sense to implement in the future.
Are you using Windows? Or some other event-handling layer (like Qt)?