I am, perhaps, seeing where some problems lie. BBO provides a Practice Table, IAC provides a Teaching Table, and they are not the same concept. What works well for one doesn't work as well for the other.
The Practice idea suits me well, but no doubt the Teaching is what many would want. It should not be all that difficult for BBO to provide both options, once they have completed the Practice option. As noted, the key would be that in teaching, one person, the designated Teacher, would be able to undo the choices made by players. I can imagine it would also be useful for the Teacher, part way through the hand, to illustrate a point by moving some of the cards from one had to another. Thus he could say "If the cards lie like this, Line A will work, but if they lie this other way, then Line B will work, and how can we decide which?" I suppose various Teachers would want various things. There is some potential here.
Maybe they are working on this.
The problem that some can listen with, say, Chrome and others cannot is a mystery to me but perhaps it is solvable. After all, we just solved the problem that I could open a Practice Table in BBO but I could not open a Teaching Table in IAC. Often these computer problems just require a simple maneuver that eludes us. We all have examples, I am sure.