This have always worked for me when I want a mino slot. I have a mino name ready and everytime I go to log in I first go to create a new character to see if I can roll this mino. When no slot is available I disconnect and go play a throw away character. While playing my throw away character everytime the game crashes or is reset I try to immediately log back in and create a new character trying for any available mino slots, this process has worked well for me in the past. The slots come available mroe often then you might realize it is just a matter of making sure your checking as often as possible.