Apparently the reserved slots are working, but it's not official yet. They don't apparently want the word out yet as they are still working on it and fixing any bug issues.
But who wants to wait? lol
If you enter it in console use this line (without vars.):
If you add it to your startup.txt use:
Take your chances I guess, but people have already enabled it and say it's working.
Note there is a delay once you join the queue, so be patient for it to kick in.