You should have some kind of “audition bus” setup to play mixes and other stuff through so that it doesn’t actually pass through the master bus for those comparisons. You can use the exact same pair of,hardware outs, but just always bypass the master bus for those things.
So you’d print a mix, it auto-imports, you assign it’s output to the ‘audition bus’ (sub-out), directly to the hardware outs, not passing through the master bus (or it’s plugs or fader trim if any). To make those kinds of direct comparisons your render playback has to be a unity gain all the way to the monitors.