I think I remember OC allows deviation of up to 1/8 inch for both exposure and nailing characteristics. I don’t think there is a functional issue of under exposure from waterproofing standpoint (May not look pretty, I’d imagine), but over exposure beyond 1/8" allowed deviation can increase the chance of nail corrosion and/or leaks. There is about 1/4 inch coverage of the nail by shingle above - 5-5/8 exposure and nail at 6-1/8 from butt edge. Either nail will have too small coverage by shingle above it if nailed properly or they were nailed too high and did not penetrate both laminates, either option is certainly not ideal. But to make long story short, I think 1/8 inch deviation is appropriate. Anything beyond is not approved by OC. In my experience, lining butt edge of upper shingle to where two laminates meet on shingle below produces a perfect 5-5/8 exposure. That is the only thing that was consistent on these shingles.