On my mv-8000 the step input has a button to ‘extend’ the current input note(s) for what you want. Really simple, same as cubase left/right for the input marker then you press the key on your controller for the set input length. Very handy to compose more melodic melodies.
If you could just do this in Cubase (simple)
- press and hold midi controller in step record mode
- move input locator (left/right) to either extend