That's mostly correct. But you need to enable PEC in the INDI control panel for the mount to actually use it. When you power the mount on, that feature is turned off until you explicitly enable it.
But yes, I used PEMPro in Windows, let it collect about an hour's worth of data, created the curve in PEMPro. Now here's the important part. It will ask you to save the curve to EQMod. Say no to that, it won't do what we want. Instead, in PEMPro, go to the PEC playback tab, and start playing back the PEC curve. Then in the EQMod control panel, expand it so all the controls are visible, and press the "record PEC" button on the far right side. That is how you actually upload the PEC curve into the mount's firmware.