[@blainedeyoung]I mean, that was always possible. Rifts themselves can be opened to just about any dimension, at any point in time. All you had to do was have the GM/a player open one to Robotech earth at whatever time period you wanted to pull from, and bring the tech/characters over to Rifts earth. The biggest issue is, the Invid can travel between dimensions similar to Rifts, and bringing over protoculture to Rifts earth would bring the Flower of Life, and thus bring the Invid. It'd be an interesting plothook for a campaign, but one that would need to be done closer to the endgame, given how powerful the Invid can be.