I didn’t fully read that link, but in the meantime I had tracked (pun?) down a solution that may be covered in that article. I can command-option-control single click-drag to emulate middle mouse button. I can now orbit in the same way shown in the video.
The one drawback I see is that SketchUp treats Option as a modifier key to say that you want to orbit off-axis.
Quickly figured out a way around that! If I press command-option-control- single click drag, I can release those keys, and get normal Orbit behavior.