Vertex's website says the Ultraphonix pedal was created to mimic the sound of a Dumble Overdrive Special amp, so I'm using the ODS-100 HRM Mid amp model as my drive and sending it into the Double Verb model to experiment with the tones I posted about. The drive created by the ODS into the Double Verb is sounding great! Reverb on this patch I'm building is a combo of the plex verb and deep space reverb. It's getting super close IMO.
(Thank you,
@ssmorga78, for the amp/cab ideas. The Double Verb was the right place to start.)