he uses our flats regularly, but only when they're NEW,
Great Attn to customer feedback!
Not everyone has the time or patience to play a single bass for 6 months just to see if maybe the set will eventually balance tonally.
I've tried several flats sets and either the B or the E and B were so far from being with the rest of the set, I just handed them off to someone else and installed different strings 'til I found some that worked.
An indication 'straight out-of-the-box' as to whether they will (or are designed to) balance is a huge improvement IMO.