And certainly, they will do it !
When looking for a methods in which they are selling tickets (especially for GA stands) and ways of controls at the entrances, I am absolutely sure that they will also do very precise check of all used pre-sale codes and in case of found doubles, they will cancel one or maybe even all transactions...
So if you need another ticket(s), after you have already used own code , then ask your wife, husband, girlfriend, boyfriend, mum, tad , Santa Claus , friend , whoever to buy a 2nd subscription and then grab those in official way.
Otherwise, when they catc