How do I change the audio render settings so that every time I render, the new audio track will automatically be in the same audio output routing as the original VST instrument track?
I am not aware of such a setting. However, in my version of Cubase 12.0.40 the rendered audio track is assigned the same output routing as the VSTi.
I used Render in Place.
Which way do you render your instruments?
Which version of Cubase do you use? Which OS?