Why have any concerns about CT when it's 4 years away with a brand new car?
Get the tires you want, there a most certainly examples which are even more stretched than this setup. Just changes them back to the original 17/18" when it's due.
You're talking about being busted at the CT however you're planning to do exhaust swap and engine mods. Neither of those will pass. (don't take it personal, just trying to clarify my point)
Anyway, these would look great and certainly interested to see some fitted pics