You can use the Xerograph deluxe exactly like the non-deluxe by simply having the envelope up/down switch set to up, the resonance knob and clean volume knobs turned off and the filter volume set to unity.
I strongly agree with you about how the Deluxe version can cop all the standard Xerograph sounds (and more) but I just wanted to point out that the regular Xerograph actually does have a resonance knob. I'm thinking you almost certainly meant the sensitivity knob?