Tryp, as stated by another poster, and also by KingLeerUK in the interview I did, when the MechLab is introduced (much closer to 1.0.0 than 0.6.0) there will be a setting such that server admins can force stock variants only, or allow MechLab variants. The devs are listening to the continuing conversation about the possibilities inherent in the MechLab, and they have as many if not more concerns than the rest of the community about its implementation. That they are taking it slow is a good thing, I think.
My further opinion that no one asked for: Introduction of the MechLab will result in massive and fundamental changes in how the game is played, and quite probably rip apart the already fragile balance of assets. With that in mind, it makes a lot more sense (to me, at least) to make sure that everything else (and I do mean everything else) you want to have in the game is already in the game, and working properly. Then, and only then, should you put in the thing that is potentially going to mess up all of the work that came before.