Wow thanks for the fast response! ^.^
As I said when I attempted to manually replace the file, I made sure to replace the Lifesupport.cfg at GameData\ThunderAerospace\TacLifeSupport, and not place it in the old location.
When I load my current save, or a new save, I somehow am getting the default resource rates.
And after I close KSP and check the contents of the LifeSupport.cfg file in my game folder to see if they were returned to the default rate, but they somehow they are indeed still the proper Realism Overhaul resource rates from the link on my last post. I also then Restarted KSP a few times after doing so and got the same results.
I reinstalled a fresh TAC as well as attempted the above twice just to be sure I wasn't crazy. Also tried manually replacing the text inside the cfg file instead, but no avail. Tested on both new and resumed saves.