Repair cafes are great for getting appliances fixed. But I think they could improve from volunteers just doing the work to a more instructional format. It’s great that you can watch them work and ask questions. It’s almost a teachng experience in that regard, but teaching is merely incidental. The repairer probes around with the DMM¹ quickly because they want to get answers quickly. Understandably so, as there is usually a line of people waiting to get stuff repaired. They don’t generally have time to explain everything.
But what if instruction were part of the goal? I would like to hang out in the workshop and watch other repair jobs and ask questions. But I get the feeling I would be in their way and slow them down. It feels like it would be unwelcome.
In principle, they could have one repairer who welcomes an audience where he describes his every move. He works slower, but ~5 or so people could learn from it. It could even be recorded and posted on peertube (not Youtube!).
Repair cafes do not accept large appliances because they are working out of classrooms and community centers on weekends, which don’t accommodate bulky things. So I have a broken refrigerator and washing machine that will not get repaired. In principle, a repairer could have a planned session and meet “students” outside to demonstrate and teach large appliance repair.
¹ digital multimeter
The process ATM already requires signing a waiver. If you bring a toaster for repair, you first sign that you won’t hold them accountable if the repairer destroys it. What you’re talking about is an expansion of that. They probably would have to mention basic safety precautions but I don’t see that as a show-stopper, at least not in non-litigious parts of the world.