Adjust Velocity While Drawing Notes

See this:

In the Key Editor, when I have to the Draw Tool active, I would like the following behaviour:

The Up and Down arrows are temporarily mapped to the Infoline Velocity.

IOW: While the Draw Tool is active, yer clicking away adding notes with one hand and you can adjust the velocity of the next note with the yer other hand on the up/down arrows without having to stop.

Click: note with Velocity 100
Down Arrow: slides Velocity to 91
Click: add next note with Velocity 91
Up Arrow: slides Velocity to 105
Click: add next note with Velocity 105

Get it?

This would be about 500% faster for me to draw in patterns.

BONUS: If I could do this with a pressure stylus (eg. a Bamboo drawing pad.)