I’ve used iTunes/Music integrated mode since it’s been around. Without it, I would drop Audirvana for some other solution.
However, I’ve always found problems with it and am sure they will not be fixed, given this is a legacy feature.
But my biggest problem, which has persisted through several versions of Audirvana, is that with both applications open, navigating the iTunes/Music UI is affected. For example buttons don’t work with a single click, but must be clicked 3 times. Scroll bar clicking is unpredictable, etc.
These bugs do drive me crazy, and I wish they would be fixed.