So are you defining "punching down" as when a man "jokes" about a woman's sex making her inadequate, or when an able-bodied/minded person "jokes" about someone who is disabled being somehow deficient?

If so, I'd agree that "punching down" is harmful, in those contexts.

That doesn't mean all women should be able to "joke" about all men whenever and however they want...or that all people with disabilities should be able to "joke" about all able/neurotypical people whenever and however they want. One can't be given a free pass for weaponizing their identity and then hiding behind it by claiming they are merely "punching up." THAT's what I object to.