Well some is better than nothing, and maybe getting our feet wet will get us to a fully automated zone eventually.
I am wondering if 2 challenges is not enough. It feels like too much of a limiting number. I'm wondering if those that watch the minor league games have a feel for the organizational philosophy on when players are "allowed" to attempt challenges. Potentially only using if it would change ball4/strike 3 calls, men on base/bases empty, # of outs. From a numbers perspective it will be interesting to see which teams/players are more aggressive and which are more conservative in calling for a challenge. Also I wonder if there will be public availability of the data on pitches that aren't challenged to see how many missed opportunities there are in a game.