Here are a couple of reference points from a torsional rigidity perspective:
The G42 m240i xDrive CLAR platform is quoted as 12% stiffer than the F22:
https://www.autozine.org/Archive/BMW/new/2er_G42.html
The G20 CLAR platform is estimated at 36,625 Nm/degree and G30 at 37,750 Nm/degree here (based on other supporting info in the thread):
https://g30.bimmerpost.com/forums/sh...21&postcount=2
The Z4M Coupe was 32,000 Nm/degree, considered one of the stiffest cars available at the time.
I would think the G87 is likely in the 35,000 to 40,000 Nm/degree range.
The stiffest road legal cars are probably Bugattis with 50,000 to 60,000 Nm/degree quoted for various models.