I have heard those DACs with my BHSE and DACT installed, and have demoed one of Justin’s units with an RK50 installed with my own NAD M51 and an Yggdrasil.
Most of my direct comparisons with volume control impressions have been with the DACT, it’s channel matching is within -/+ 0.05dB vs the RK50 -/+1dB -100dB to 0dB.