This is a wonderful idea, and I've got no idea how to actually do it in a standardized, rigorous way. Vendor claims are often contradictory, it's hard to get a good idea of anomaly frequency, availability is... a rabbithole, and it's hard to come up with a standard taxonomy of anomalies--most of the analyses I do wind up finding something I've never really seen before, haha. With that in mind, I've wound up letting the reports speak for themselves.
Also, ideally the analyses should be rerun automatically (or possibly after being paid, but making it easy for the company to do so) every time a new major release happens rather than being done once and then being stale.
I don't know a good way to do this either. Each report is typically the product of months of experimental work; it's not like Jepsen is a pass-fail test suite that gives immediately accurate results. There is, unfortunately, a lot of subtle interpretive work that goes into figuring out if a test is doing something meaningful, and a lot of that work needs to be repeated on each test run. Think, like... staring at the logs and noticing that a certain class of exception is being caught more often than you might have expected, and realizing that a certain type of transaction now triggers a new conflict detection mechanism which causes higher probabilities of aborts; those aborts reduce the frequency with which you can observe database state, allowing a race condition to go un-noticed. That kinda thing.
If I'm lucky and the API/setup process haven't changed, I can re-run an analysis in about a week or so. If I'm unlucky, there's been drift in the OS, setup process, APIs, client libraries, error handling, etc. It's not uncommon for a repeat analysis to take months. :-(