I really like flying VTOLs/hovercraft with the Translation module. I think it'd be nice to have a +1 and -1 button to change the Speed as an alternative to clicking into the field and typing the number, which can be sometimes difficult while also controlling the vehicle.

Sounds like it could be done quickly. However, might it make more sense to have a text box that has the increment number that you can type in, and then + and - buttons that actually change the translation speed? (Much like the Maneuver Node Editor tool)

Yeah that's even better!

I totally support this request.

I currently use Diazo's Vertical Velocity mod for this feature.