Yep - this is what I do.
For example, set the harmonizer to play a diatonic 3rd above and a diatonic 5th above, then set the expression pedal to change the top harmony between the 5th and a diatonic 6th above - which gives a first inversion chord (with the note played on the guitar being the 3rd).
For example, in C major if you play a C the harmonizer gives an E and G, but sweep the expression pedal and it changes the G to an A, giving Am first inversion. Or play a D and toggle between D minor (D F A) and Bdim first inversion (D F B) using the expression pedal.
To play a I - V - vii dim (i.e., V7 with no root) - vi: play a C in heel position (C E G), then play a B in toe position (B D G), then move the pedal to heel position to add the 4th scale degree (B D F), then play A in heel position (A C E), or play C in toe position (C E A) for a different voicing.