Direct and integer mode

What does direct mode mean for SQ?
Is direct mode needed for integer mode?
I ask the question because I’m confronted with the ‘Terrible Mac Core Telephony Trace’ bug, and none of the easy solutions work for me. Seems I should upgrade to Mac OS Sierra. But the so called ‘Direct Mode’ is reported not to work with Sierra. And with Audirvana I know Direct Mode is needed for Integer Mode. Roon’s User Guide is not very clear about what Direct Mode means, and if it is needed for Integer Mode. With Audirvana, SQ is clearly better in Integer Mode on my system. Can’t try this out anymore with Roon, because of the terrible Core Telephony Trace Bug. It simply is not possible to start Roon!
Computer audio: grrrr…