Trainers are NOT written for beta version, just latest stable public release.
They do not regular update the game anymore and the last updates are only available on beta. They said they do not publish it to the release version on purpose because some changes in the gameplay. However it is stable. They told that in one of the lasts dev blog.
Do not get me wrong I am 100% agree with you with 99,9% of the games but it is a little bit different with this game.
Thanks, its our new template we will use for upcoming game releases or port some existing trainers to it like this one.