No, it has rather obvious technical implications that people like to pretend do not exist. Those features people use are effectively not portable to other platforms short of making iOS run on other people's hardware. Sure, the messaging might be portable, ignoring the security concerns, but iMessage is used for a lot more than that.

In short, any portable version would still be nerfed, just slightly less nerfed than the current situation. The green bubbles would still be there to indicate that their platform can't support core functionality of iOS inside of iMessage.