FF, I disagree.
Correct me if I'm wrong, but it doesn't say "only" anywhere. It's just that a successful flight test is the only case listed (other than cases which specifically relate to a multi-crew environment).
By the same token, though, it "only" lists a couple of cases where PUT can be logged (training for a license, rating, or conversion onto a different aeroplane within a class, and an unsuccessful flight test) - and a club checkout is none of these.
Because there is no "only" or equivalent, my conclusion is that either is
probably acceptable, but it is so open to interpretation that it is best to err on the side of caution. And it's so easy for the CAA to clarify.
FFF
---------------