In videos it's a super powerful tool, but when I open it I can only edit like one short note at a time, and even then it's hard to make sense of it. What am I missing?
It's only possible to use Harmonic Editor on one note at a time. Click on a note to display its harmonics in Harmonic Editor. A description of the currently selected tool is shown beneath the tool buttons. More information can be found on page 42 of the manual which can be opened from RipX's Help menu.
"Harmonic Editor
Listed under Effects, use this tool to view the harmonics of selected notes and edit them in powerful ways."
You may want to change "Selected notes" to "a selected note", as that was what confused me.