My one complaint about the NiBL is that the IEMatch section has a whopping 4 ohm output impedance - which totally ruins the FR for certain IEMs - missing the whole point of using that port in the first place. I just don’t get why they didn’t include the tech from the dongle with the ‘ultra’ mode. It’s clearly doable. The main port is great though, and I’m a fan of that DAC in general.