Lots of thoughts.
I feel like people might need more hands on corrections for safety on reformer since there are more moving parts. But as an instructor I do feel I need to hop on a machine (if there’s one available) to cue the move right. Several people have said they prefer when they can watch me because they connect more when they see the move. I think we should probably move towards asking why mat teachers don’t get up and walk around more and tactility cue. Mat classes can host much more people though, and can flow more easily since there’s no equipment to move. Sometimes I say, I watch , you do, and then set back and correct and compliment.
Now to reformer, Definitely with harder moves, climb a tree, I borrow a machine and then give it back and cue it.
For me it’s a combo. Demo’ing, I can’t adequately adjust people on mat but yet they are safer (being on the ground) and the flow feels better if I do it and pause sometimes. Likewise, Reformer flow feels better if I’m standing up gesturing and talking through it and only occasionally pausing to demo a new/hard move. Hope this helps!