FYI, I had to add to my SC coolant several times after the first several start ups. Not alot, but several ounces 2-3 times to bring it up to correct level.
I have a 2020, and 5k on the maggie and it runs excellent on Daves tune.
Did you take time for the tranny to "relearn" the shift points? You have to do that. Drive at various speeds under normal conditions for a while. At first, mine wanted to stay in 3rd gear and would run the rpms near red line. But now that it has learned the shift points, my fuel economy is actually better than before the Maggie. Of course, I will never save $8700 worth of gas. lol. But now that it shifts when it should, it is a demon. Mine is a Rubi with factory 4.10 gears and 37 x 13.5 Nittos.