Boy does your topic take me back a few decades, Jan. TY for starting the conversation!
I've been both an attendee & a teacher for day-long seminars. Most of my attendee ones were ones my (then) craft store employer sent me to & ranged from painting thru florals. My stints as the conductor of daylongs was always on behalf of manufacturers.
One of the many things I learned on both sides of the classroom was that the ability to sustain 'focus' was always best when the instructor was able to 'read' the class/audience. Spurts of intense doing/learning with a short breather were part & parcel of the best ones I attended. And most of the daylongs I attended/taught were open to crafters of all levels--from know-nothing to know-everything.
. A good instructor can handle the range. He/she learns to work with the wanna-learn & smile @ the experts who (often) want to be the teacher.
For me, a 'good' teacher determines what the focus needs to be every step of the way & assists both the individual student & the entire class in sustaining the focus of the moment.
As a fellow 'multi-tasker', Jan, I can definitely understand where you're coming from. That said, however, I'm less inclined to multi-task as I've gotten older. I'm trying to remind myself to be involved in the 'now' in learning--rather than letting my still fertile brain lead me off from the at-hand task.