In my opinion the Native Instruments B4 II is the Gold Standard for B3 emulations, even though it is only 32-bit, but it too does not have a tuning feature. However, what it does provide is a range of Classic B3 presets that are pitched in a range of tunings either side of the standard 440. So if a piece needs to be played in something other than Concert pitch, a correctly tuned preset will probably be available.
Perhaps this idea is something that Arturia might consider implementing in their B3 emulation.
