I'd be concerned about inexperienced paddlers in solo boats for the first time on Superior.

If the weather permits practicing rescues would be a fun afternoon.  Everyone in their boats.  Learn how hard/easy it can be to dump a canoe kneeling/sitting hands on/off the gunwales.  Solo self-rescue, canoe-over-canoe rescue.

Even if folks learn they can't do it they would have that much more self-awareness.  Trouble happens when people push their limits.  Tragedy happens when they don't know what to do or even what they're capable of after they're in the water.

For example, I know from trial & error that I can't self-rescue in my canoe.  Should I dump in a serious situation I know I'm not going to waste time, energy, heat trying to get back in the canoe.

Otherwise don't sweat too much over it.  Odds are that nothing bad is going to happen.
Painters on all boats.  PFDs on at all times.  Most boating accidents are the result of poor judgement & plain honest stupidity.