If I'm on one Steam-account (lets call it #1), play a character on a server, and then logout and quit, and then quit steam, login on another account and start DayZ, the play-button in-game will reflect the former accounts last played server, but not this accounts last played server and this if you just press play, it'll go to the 75 second waiting time which you have to abort. Clearly, separate Steam accounts should have separate saved settings for last played server.