Can the output channel number of JUCE plugin follow the output port of the track

1

I create a stereo audio track, but I found I can still set the output port to 7.1, 5.1, etc.

Now I wanna write a plugin with my upmix algorithm from 2.0 to 7.1. Can I make it with a stereo track with a 7.1 output?

P.S.

  1. I can make it using a 7.1 track in Nuendo, Reaper, etc. by add clips to the first 2 of 8 tracks, but I cannot make it using Pro Tools because PT doesn’t allow clips with different channels from the track’s, so I must make it with a stereo track.
  2. I found some plugins can output more channels than the limit of the track, 360 WalkMix for example (it can even choose audio devices). I wonder how 360 WalkMix makes it.