I've had the same issue back in 2018. I had three instances of BlueARP targetting different VST instances. Played just fine, but nothing in the mixdown. Any ideas if this has been fixed/resolved in newer versions of Cakewalk? If not (given that 2021.09 is getting some improvements to how exporting audio works) perhaps we could bring it to the devs' attention? Or perhaps make a feature request for native support of VST MIDI (note generating) plugins (so that we don't need to do all this magic with extra tracks and "wiring")?