I got an older vette and first then I did was headers, off road X and straight pipe on my road to boost. My 2018 Mustang with a melted clogged cat was a good lesson.
Don't think I have seen anyone on a 18+ Roush get into the low 10's without E85. One of the guys around here tried but could never get it to launch properly. He ended up selling it.
Btw, just noticed you're in Michigan so close to me. What track was this at?
Obviously you would know since you have owned both but on the other hand.. For example just picked up a 1999 Corvette. Is it superior to the c5 zo6 a base C6 for a little bit more? No not even close and no one thinks it is but I liked specific things better so to me it is better. And I can...
Most Likely the cat will decide you are his\her preferred servant. Murdering you would be way to easy. It has nine lifetimes for you to serve, consecutively. Then you have permission to die.
5 Ways Your Cat Is Like Royalty - And You're Their Servant! - CatTime
It's transferrable. How that happens isn't detailed in the manual just that it is. And having owned a Roush usually everything is handled directly with Roush