Far as I know the Master and A1 sliders have an effect on Rendered tracks in RB.
Can you post an image of the RB setting you think should change? Just to help define/clarify.
Your above image is of BiaB, which is different in many ways (including signal flow)
There are other places to control the main out in RB, and one of them I never fully grasped is the All slider in the mixer (between the left & right panels).
I *think this gets saved per project, so maybe that is where you could adjust it and save it as a test, though my *understanding* is it affects everything down stream, so it would still affect renders of a mix.
Maybe not the 'Save Track to File' action, but actual Render actions, where it runs thru the right side of the Mixer on the way out.
Again, this is just my understanding/experience with RB
FWIW, my normal settings for RB outputs are shown below .. and it doesn't blow my ears out.
Yes they are different than my BiaB settings, but they are different programs.
I'm wondering if something else is causing this, cause I've been using RB a long time without experiencing this issue