Regarding your Mackies, which exact DACs and sound cards have you tested them with? According to the manual [1] they expect a +4dBu input, which will lead to unnecessary noise if you use them with "consumer" -10dBu gear. Most audio interfaces (i.e. designed for recording, not Schiit-type DACs) with balanced output will do +4dBu - I believe it's standard on all Focusrites.

[1] https://www.hhb.co.uk/files/product/file/user_manual_2013112...