It would really depend on the specific tire, and what you do with it. Probably not a great idea for taking a road coarse, not a big deal in a straight line or daily driving and such.

The wider tires just generally offer a little less lateral stability. Obviously if you go way too big it'll likely pop the bead or damage the tire under too much load.

 

I assume OP uses his vehicle as a daily driver considering he reached 30k on Pirelli summer-only performance tires. In his situation upgrading to a 275 width on factory wheels won't present a problem.

I agree that for road course situations it would not be ideal. I don't see how upgrading tire width by 20MM on factory wheels is 'unsafe'.

People do it every day. I've put wider tires on just about every vehicle I've owned; cars, trucks, and bikes.