I'd be worried about the name difference thing, purely because I've experienced End of the Road's admissions/security systems and found it to be weirdly over zealous.
A few years back I lost my wristband while inside the festival and went to the box office to get it replaced. I had my ticket print out with me, showed them my email confirming my purchase, proved my identity to them. The box office team were lovely but they had to radio their bosses to find out what to do. From that point on I was treated more or less like a criminal, the assumption being that I was there illicitly. Their response was to pass me on to site security who escorted me to my tent so I could pack up and leave the site. Fortunately as I decamped I found my wristband which I'd either removed in my sleep or had somehow slipped off while I slept, and I got to stay but man it was a horrible experience and tainted my feelings about a festival I love.
Just saying, don't rely on common sense or good nature or even solid evidence winning out with these people. They have strict guidelines and, in my experience at least, prefer to assume you're up to no good and deal with you under that assumption. I would get it sorted beforehand.
