SOLUTION!
I was able to get Hermod to sync with Pamela’s New Workout with the PEXP-1 expander and an iConnectivity mio USB/MIDI Interface. Hermod “Clock Source” is set to “Host Port”.
Pamela’s New Workout → PEXP-1 expander MIDI jack → iConnectivity mio → Hermod “usb host” jack
Now, pressing the Start/Stop button on Pamela’s New Workout controls Hermod perfectly, without any skipping or latency that I can detect.
Here’s a link to the iConnectivity mio USB/MIDI Interface:
Aside: Hermod should really support 24 PPQN