I had missed @dcrainmaker’s post, thanks. That helps with the adjustments.
I’m not sure this is good enough. It’d be nice if they included, say, two sets of markers or “stoppers”, which would allow you to quickly adjust the fit from Rider 1 to Rider 2. With “stoppers” I mean a mechanism that either increases the resistance as you move, say, the “stem” across the “marker” or blocks movement outright. Or alternatively, these markers act as hard limiters of movement where either “extreme” corresponds to the setting of one rider.