We tune down a half step in both my bands, and have done so in one band for years, to help with vocals - a half step can make all the difference. After playing regular basses, I was eager to get my first Dingwall so that the longer B would still sound good detuned. It does, with no adjustments necessary, even on the SJ4. I even use a low A some on the sixer and the fives, and it still feels good, but that's about the limit. All of my Dingwalls are played, and rested, detuned 99% of the time with no issues.
Mark