Harbinger 1.5 Controlling LFO Pitch Amount

[Spacecommandant]

This is a great sounding effect. I've been playing around with the various pots and trimpots and to my *imperfect* ears, in the vibrato mode, the amount the pitch is modulated is, let's say, a semitone. So, the signal warbles up and down a semitone and it seems that the Intensity knob attenuates the amount that the semitone warble is heard, but it doesn't change the amount that the pitch changes, if that makes sense. Adjusting the internal trimpots, to my ears, also don't change the amount that the pitch changes, they just alter how pronounced or audible it is.
So, my question is: am I wrong about this, and if not then what specifically could one adjust to control how 'far' the note is bent? Is there a practical way to have a knob which can expand or contract the amount of pitch bending, so as you turn it clockwise the warble increases/decreases in pitch?
I hope this was clear, thanks in advance....