Would these qualify as high-capacity, chemical-laden, assault extinguishers with no legitimate fire-quenching purpose?

You don’t need a fire extinguisher — just call the fire department. They’ll save you.

Oh, and let’s not forget that there is no mention of fire extinguishers in the Constitution or the Bill of Rights.

I mean, why would somebody want to have an extinguisher unless they were planning to start a fire somewhere?