I would love a Kodabromide / Brovira type enlarging paper workshop since enlarging paper is my main interest.
I would also suggest that the workshop beeither four days or a full week. Include a day of revue and lecture on new material plus time to evaluate coating problems and successes. I would also suggest participant bring prints of work to share at the workshop to give feedback on their work at home and to aid in diagnosing specific problems they are having.
All the best