Great. Not surprising it was easy, those bolts dont see enough moisture/road chemicals normally to get that rusty or propagate deeply. Nothing like the Intake manifold bolts are capable of on that engine. The heat from drilling was enough to loosen the minor corrosion.
EZ outs are worthless for DIY auto work. If a fastener can come out with an EZ out, it will come out with some other less risky and more advantageous method.
EZ outs are excellent tools in highly controlled, precise, and curated machine shop type settings, but they’re trash in a shop that sees real live, on the road, significant corrosion in the middle of a job. EZ outs simply don’t work at all in rust prone areas / you need LH bits and heat.