In Telluride I had to pull off of the road because the fuel pump was cavitating and the engine quit. I suspected excess pressure in the tank as the culprit due to a faulty evap system (this is before I realized it was the fuel boiling) so I unscrewed the gas cap. The pressure blew it out of my hand and a few feet away in the parking lot. The vapor coming out of the filler neck was ridiculous. It continued to come out so fast it scared me so i got the dogs out of the car and we sat down 50 feet away or so to let it do it's thing. I swear it didn't slow down for 10 minutes. eventually I replaced the cap and drove it to a gas station where topping off with cold fuel fixed it.
I think keeping the fuel system closed up where the pressure can build is really the only way it'll work at high altitude and high temperatures. Even though our older fuel systems were not designed to work like that.