Did my first rescue course in sidemount the other day, everyone in sidemount. there are some skills that a back mount BCD is needed so the students can master the skills but else it's all easy and fun. When letting students realistically practice dropping their own and student gear, In sidemount they just clip of the tanks to a nearby float and keep the harness, making towing much easier. Some of the surface skills thought are a little harder or require rethinking the skill a little.
But all in all rescue in sidemount was not as hard to teach as you'd imagine we did most of it with 2 tanks, however for surface skills, we dropped one, else it was very demanding and would require spreading the course over more dives.
Would love to hear about any results others have had.