Automation: "Scale Vertically" not working for values = infinite

I have an automation lane where the value is infinite, e.g. a send automation.
I want to mark an area and select “Scale Vertically” and dragging mouse up.
This is not working when the initial value is infinite. If the value is other then infinite it works as expected.

1: Is there any reason for this behavior?
2: Is there hot keys for “Scale Vertically” up and down?

1: Use Shift-Arrow when value is infinite.
2: Unsolved