I have a second name registered for when I was doing Edinburgh 1575 (ancient history now - I don't do that anymore). It gave me satisfaction, it only costs a few dollars. But don't expect friends who know you as X to call you X one day and Y the next. Changing your name completely is hard enough. Switching back and forth will only happen for a few very close people who 'get it' and maybe not even then. I say just do it in your own mind if it is fun for you. When I was an active fighting squire to an active knight (also ancient history) I dressed as a boy because it was way too much work to get completely into girl stuff - not always able to shower or even clean up in a sink, different underlayers, different shoes, different hair, different hat. Too much crap to carry to a day trip, so I was Giles (ZJeels) which is actually a joke only a belgian would get. (Giles is a character representing the town of Liege at major street festivals, and he is a mischievous character who plays pranks and is likely to be the one cuckolding all the hard working husbands - I guess the american southern equivalent is Jody).