I could make some exceptions. But they are always muddy and again always stem from having trouble understanding the trinity.

I think Nestorians are about as heretical as you can get and still be saved.

Maybe 'Arianism', but not Arianius himself. He studied the Bible and was clearly an intelligent guy. But the hovel peasants that heard him or his followers and went "okay that makes sense" I could see some form of mercy being given to.

Wouldn't want to risk that though.