The thing about every build released in a beta is that it is deemed acceptable for release by Apple’s QC reviewers. A “Q” released beta should be just as fine to the public as an “A” build: they both passed QC, presumably with the same requirements to do so.
The difference is how they got there, i.e., how many times it took to get a passing grade. That’s more a problem, I would think, for the developers, who need to refine their code so it performs as intended the first (or first few) compile(s).