Seems like you would need to rip out all the seats for a significant weight savings to see better 1/4 mi runs. Honestly, to me at least, it’s not about running 1/4 mi or 0-60mph at the track because the MS Plaid blows EVERYTHING away, even 100% bone stock with stock wheels and 1-5 people inside the car!
Yes, one reason why I bought the lightweight forged Signature wheels is because of the unsprung weight reduction (thinking it would be a touch quicker) but mostly, it was because I liked the look of the wheels better than oem stock Arachnids or the Tempest wheels and wanted my MS Plaid to be a little different than most others.
So it would seem that changing out the wheels to reduce each corner by 10-12lb or whatever makes virtually no difference in performance at least in terms of how quick the car is. It could help with performance in terms of cornering and handling though; that’s a little more difficult to capture data on though.