I think you're trying to formalize all that a bit too much, guys. The Natural Volume values are a good starting point - for a pre-configured template, for example - but not a set-in-stone scientific formula for a perfect mix. Don't overthink it! If something's too loud, turn it down.
I, personally, am perfectly aware that I'm "formalizing" here, but it's important you stress that! π However, and I can speak just for myself, my experience in this field is so little that I need such formulas for starting points. Some kind of guidance to compensate for a lack of knowledge.
If one tells me, "those are good basic settings, leave those settings untouched, because that's the way it is, but fiddle around with these to your liking", then I'm happy. (Which happened here. :P)
With the MIRx offsets, for instance, I feel that the flutes are too soft. So are the oboes and clarinets. Yesterday, I heard a rehearsal at the Musikverein in Wien and I tried to focus on the woodwinds for that matter. I could clearly hear the flute at all times but wasn't really able to distinguish the clarinet and oboe from the rest of the orchestra. My fried told me that, generally, the latter two need to be exposed and separated by the composer/orchestrator to be clearly audible, otherwise they just color the tone or merge with the violas for instance. --> turning the flutes up in my mixer would have been the right choice, possibly. But turning up oboes and clarinets maybe not (in my particular case they play in the same register as some other instruments)... do you see where this is going? π
All the best,
Lukas
PS.: I LOVE this forum... π