That's where you get into the debate of the need to look at RT3. If you supply T4 you will increase RT3. I know it helped me to lower RT3. Then you have some say its foolish to mess with it. If you feel better lowering it that sounds good to me but if you can't handle seeing the T4 being lower it may not be for you. You would need to fix why RT3 is high to keep it in range.
What helped you lower your RT3? T3, or are you saying T4 helped you as well?