From my observations, not that many are (yet?) interested in the pursuit of constant development towards a (more) complete athlete. Even less so in ambidextrous fashion. I would estimate <0.1%, even within the physically active community.
Overall, we might have 3 groups:
1) Not interested
2) Theoretically open but not really into practicing what's different and at first uncomfortable
3) Similarly interested
For Group 1, I'd say save what they want to do for playing / working out / interacting with them. For example, if folks had been looking forward all week to switch off and just play a set of tennis after a short warm-up, then maybe that's what you'll do. (You can always do the other things before and after...)
For Group 2, you might demo something you've developed elsewhere or negotiate a little developmental segment into your session. For example, maybe get "permission" or even support to hit 5 minutes forehands on both sides, or get 3 serve attempts incl the 1st off the weaker wing for a set, or warm up barefoot. Would still suggest checking in and/or asking afterwards if that was OK and what to do different next time. Maybe you'll be so inspiring to move your partner(s) closer to Group 1 :)
For Group 3, those are really your like-minded peers. You can exchange and iterate what you want to work on, and try different ways to get there. What exercises (and/or play) help both of you? Alternate what benefits the other person? Can you switch assisting, e.g. feeding balls?
My personal goal would be to see more of Group 3, to maybe go from <1% to >=33%. When teaching tennis, also in the spirit of "Backhands Optional", I've already tried to switch more towards a "see and help yourself" approach. So e.g. if you have a small group, show them ways to train each other early on...