I have an old Milwaukee spline shank rotary hammer that can be operated with or without rotation. As others have stated, that’s the type thing you really need.
Thing I’m not getting about how an impact wrench would work is the “hammer/impact” part of a rotary hammer and impact wrench are totally different. For a rotary hammer the impact is front to back, more like a Sawzall than an impact wrench. I can turn the rotation off on mine and use it with a chisel or bull point as a small demolition hammer. It’s that jack hammer chiseling motion of the rotary hammer that allows it to efficiently punch holes in masonry and stone.
An impact wrench hammers in the plane of rotation. That’s great for busting a stuck nut loose but doesn’t do anything but spin a drill bit against a concrete slab.
Rent, buy, or borrow a rotary hammer.