That's exactly what I'm finishing today. That foam board works pretty good and is super easy to work with. Also make sure the air seal is good. I used foam tape where the hatch rests against the frame.
When I crawled up in the attic, I found where the previous owner got halfway done and just gave up. There's still 4-5 unopened rolls of insulation just setting in the corner.
If it was just that one thing, I wouldn't either. But I'm impressed with their half-assing ability. Last year I was mounting an outside mini-split unit and found where when they turned a porch into a bedroom, they didn't bother building an external wall. They put up studs, drywall on the inside, nothing but foamboard and vinyl siding on the outside.