I had this idea as an analogy to the runaway greenhouse effect. How do you stop a runaway greenhouse effect on earth? Stop runaway consumption of fossil fuels! Maybe runaway consumption by black holes can be stopped. Or rather, maybe it is the exception rather than the rule.

Maybe Kerr black holes don't grow, maybe they reach a maximim size, and thereafter deflect all incoming matter. Maybe only Schwarszchild black holes are susceptible to runaway consumption. To create one would require that incoming matter continually cancel out any angular momentum. Extraordinarily improbable. That could make big bang-type inflation events exceedingly rare indeed. Now I have to come up with a reason why Kerr black holes might not absorb matter beyond a certain size.....

Or maybe all black holes grow. And maybe there is a way to stop it but it requires intervention by intelligent aliens curbing its consumption.... Smart! And curiouser and curiouser.....