I wouldn't call 8k common, but it's not unheard of. For the '13-'16 cars bumping it up to ~7,600 is really common and gets you ~60mph, going to 8k gets you ~63 mph. The '17+ MT cars have a shorter final drive.
http://www.precisionsite.com/auto-x/tools/
I played with the math for the first time ever, if you're on the rev limiter for 1s at 7,600 rpm you can cover the same distance in ~0.95s at 8k rpm 63mph so if you can maximize it you're looking at up to 0.05s gained there and that's a linear scale so 2s at the 7.6k rev limiter is 1.9s at 8k rpm, 3s v 2.85s, etc. And that's being favorable to the higher rev limit as I'm not bothering to portion out the time it takes to rev past the lower rev limiter and get up to your new max speed.
risk vs reward, I throw away far more than a tenth of a second on dumb mistakes so upping the rev limiter isn't a priority for me, but avoiding engine troubles is.