Unify's built-in PhaseMod effect is a stereo phase-shifter (phaser), derived from open-source code in Paul Batchelor's Soundpipe project (see https://paulbatchelor.github.io/res/soundpipe/docs/phaser.html).
A phaser is essentially a notch filter whose center frequency is swept up and down by an LFO.
The PhaseMod GUI features eight control knobs and two checkboxes, each corresponding to an identically-named parameter available for modulation, as follows:
The original Soundpipe code, on which PhaseMod is based, was not well documented, so the above is all the detail we have at the moment. Experiment with the parameters to discover what this effect can do.
Like any phaser effect, this one works best on harmonically-rich sounds. You would not hear much effect on a sine-wave pad sound, but switch to a bright sawtooth sound and the difference will be very striking.