Hi Matt… Sorry if this is way too late but perhaps for the benefit of others… Independent of any floor installation concerns, I would seal it just to reduce radon gas. I use to live in an area of the country where it as heavy and years ago we replaced carpet on a slab and did radon readings before and after but we sealed all cracks, even hairline ones and actually sealed the surface as well. It made a significant difference in the gas level afterward. Of course, if radon readings are very high there is venting equipment people can get installed.