Multiple instrument-tracks on same instrument

I have 2 plugins from Spectrasonics:

Stylus RMX and Omnisphere

They have 8 channels in one instrument. I create an instrument-track, and then I can use one channel in the plugin in that instrument-track.
The other channels has to be on midi-tracks. The possibilities in midi-tracks and instrument-tracks are not the same (obviously), and if I have to make an instrument-track each time I need Stylus RMX or Omnisphere, it will probably become very CPU-usage-heavy.

Is there a workaround for this issue, to have multiple instrument-tracks on the same instruments different channels?

Thank you in advance.

No… create a instrument track and load your instrument… select the instrument track and create (for omnisphere) 7 midi tracks you will see that the instrument track have the midi channel 1 and the other midi track have 2/3/4/5/6/7/8 midi channel each so with the multi out avaible in instrument track too you’re ready to use the 8 channel of Omnisphere separatly with only one instance of Omnisphere…
Hope That clear…

There is a balance between too many instances of the VSTi straining system resources vs. too many MIDI tracks pointing to the fewer VSTi instances. I’ve read the latter can strain the system with high ASIO meter avg. load and real time peak (something about not spreading the work among the CPU cores as optimally as having more VSTi instances).

FWIW, I think I’m getting better performance/less dropouts by lowering the number of MIDI tracks pointing to a single VSTi, and instead increasing the # of VSTis.

Can anyone who knows the details fill in the blanks here, or correct as needed?