Imo......
All the tuning suggestions will slow the car a bit, here and there. But the o.p. wants to slow the car from low 10s (10.20 or so?) to 10.90.
I would figure out how to make the stop the o.p. has, in post#9, work. Most consistent, easiest way to kill a substantial amount of time without altering much else. Just keep an eye on the tune and exhaust temps as GTX John says.
Probably easier than adding 500-700 lbs.