Plugging to 50 amp is beneficial at times...
1. My 30 amp plug in at the campground had an open ground. So I plugged into the 50amp with the pigtail adapter.
( If there was no 50amp I could have plugged into the 20amp. Or I could have asked for a repair person to fix thier socket.."" good luck with them fixing it day of stay though..LOL""" )
2. Was at a site and so many were using the a/c the voltage drop for the campground was horrible. Was running at 100volts at times. Kind of a brownout condition. I said no way. I went out and hooked to the 50amp with no issues with power fluctuations..
Now when I am camping I hook to the 50amp if its available before the 30amp. Most of the older campsites have bad electrical fluctuations..