Thanks to Robert and everyone involved with Myfocuserpro and myfocuserpro2.I can confirm the original driver (when modified for WiFi) works for the ESP32.
I followed his suggestion to change from SERIAL to TCP, and changing Firmware version in my clone of the myfocuserpro2 indi driver.
I would have gotten there much sooner but I kept installing the driver's XML file in the wrong place.
My breadboard setup works as expected. I learned so much about drivers and have an appreciation of the effort that goes into all the open source software we have.