[...] So if I understand correctly, adjusting that little circle, after switching to bus routing, controls how much of the MIR "wet" signal goes to the bus? And best to keep that circle @ 0 db? [...]
Exactly.
... in 99% of all cases there's no need fo the extra rotary fader, actually. From MIR Pro's point-of-view the routing option would be sufficient ... I think it was the VE Pro software-engineers' way to say "See, that's some kind of 'send'- option, now." 8-)
Kind regards,
/Dietz - Vienna Symphonic Library