Thank you for the best working USB-MUltiboot solution (at least for me). :)
Recently I had to enter the Generíc Windows setup key multiple times for different setups. When choosing to manually enter a key in E2B, the description says something like "25 digits". So I sometimes entered the key unhyphenated (without dashes) because otherwise it wouldn't have been 25 digits, but 29. Of course this was wrong and I had to enter the key a second time, including dashes. So I wanted to suggest that you might add a little hint, that dashes have to be input, too?
Subject Manual Key input for Windows description