I've suffered from CHs for 25 years. They used to occur every year or so and last 8 weeks. Like many CH sufferers, I'd rather "check out" than face a full-blown cluster without oxygen. Thankfully, high-rate oxygen always works for me in 10 minutes.
I've been able to skip a few years by doing the following: at the first indication of a shadow, completely cease both alcohol & exercise, and start taking 100 mg of caffeine every few hours.
My neurologist told me that there is not only one pathology for CHs. I guess there are different types. For whatever type I suffer, during a cluster period, vasodilation sparks a CH and vasoconstriction can prevent/abort a CH.