The ebuild by default keeps one time password support disabled. I do not see a reason why. This is the best way how to login from a coffee-shop and we just accidentally prevent users from using this feature.
You don't turn on a USE flag and magically start using one time passwords. To use otp, you need to initialize the user, print the passwords etc which presumably means you know what you are doing. Turning on the otp USE flag is just one step in the whole process. In other words, otp USE flag only enables support. I am not going to turn it on by default as the user base is rather small. Closing.
