I’m so grateful for people like you with such deep experience and such a detailed way of relaying information that we can all use.
I am now actually very intrigued to read what you think on my new thread (click here), albeit regarding Cubase 11 Pro, that touches on a similar issue that I need to solve with my Mastering Engineer.
Again, I note that no touches were made whatsoever to any faders at all. The only difference is that I selected my Master Output (with no inserts anyway) instead of the specific Channel/Instrument/Group for exporting stem mixdowns.