I always thought that even if you go the large wheel + low profile tire route one should keep the pressure to what's recommended by the manufacturer. However I noticed that some people swear by increasing the pressure significantly when they switch to low profiles.
For example if the manufacturer recommended pressure shown in the owner's manual or on the car body is 2 bar - they'll pump up 3 or even 4 bar for every day driving. The reasoning behind is that in poor road conditions there is a lesser chance of damaging the wheel upon hitting a pothole. Which makes sense, as the wheel is closer to the ground with low profile tires. Higher pressure will make the tires compress less and give the wheels a bit more clearance. I've also heard claims that that the recommended pressure values are for maximum comfort, and higher pressure will improve steering response and cornering stability.
And to be fair, for many cars large wheels and low profile tires aren't among recommended dimensions anyways. It might not make sense to cling to their pressure recommendation when the largest wheel the manufacturer recommends is R16 with 215/45 tires and the owner fit some R18s with 215/30s.
So, should one keep the pressure to what's recommended by the manufacturer regardless of the tire dimensions? Is it beneficial in any situation to increase the pressure of low profile tires? How much is alright without wearing down the tread unevenly?