Then, maybe look at the IEM ambisonic plugins: you can have a monitoring track with a binaural decoder for monitoring on headphones, and a "speakers" track on which you can setup the 5.1 array with the AllRADecoder plugin.
You can find an AllRAD json configuration file for the 7.1 setup here:
https://git.iem.at/audioplugins/IEMP...s/7point1.json
This file can be loaded in AllRAD to view and edit the speaker setup (you can remove the extra side speakers to make it 5.1, or create your own 5.1 from scratch).