I got in at 12:01am. However, I was NOT allowed to choose the time of day I wanted to ride the attractions. Rather, I picked the attractions that I wanted (if I picked fewer than 3, the site just gave me whatever it wanted to throw in there for the 3rd), I was asked to prioritize the rides in order from most preferred to least preferred and I was given 4 options: Option A, Option B, Option C and Best Option. It was very frustrating as there were few morning or early afternoon options (which are important to my family as my mom needs to rest in the afternoon having just finished chemo and radiation by the time we arrive).
After calling there to find out why I could not choose the time of day I wanted, I was told it was still testing and that they hoped to have that option available soon. The CM asked what time I wanted what attraction in MK and went to over-ride the FP+ selections that I made, but even her internal system showed no availability. She said to keep checking because they hoped it would be working soon.
One tiny bit of hope that she did give was that the testing would be going into April and she said that it was likely there would still be legacy machines available for some attractions. God, I hope she is right, but I took her information the same way as I would that of a bus driver.