I thought MQA on the MS600 was definitely a non-starter? I mean, I'd be overjoyed if this was not the case - as a happy MS600 owner - but given the relatively new Explorer 1 couldn't be upgraded in firmware, I am a bit of a pessimist about an older hardware design making the cut.

Office: MacMini + Roon -> MS600 -> AR LS-9 -> M60s (1993 vintage)
Home: [AppleTV -> HD621] + [Roon -> 218] -> G65 -> DSP5200HC + DSP5200s + DSP3200s
Being a JAFA in Auckland, New Zealand