Considering the Physics I doubt it would do much damage if it did fall
off. The blade is well balanced, operating well within in it's stated
design speed. If by some miracle it did break free, there is still a
full 360 circle for it to to choose an angle for it's escape path.

I agree with that, I've had a lawnmower blade come off at full throttle
and it just spun into the dirt. If it hadn't been needed as a flywheel,
it might have gone unnoticed until the unsatisfactory cut started an
investigation. I was more concerned with the safety of bystanders. In
the hands of a relatively careful operator, I doubt anyone would be
hurt, but there are some pretty serious idiots out there.