Moving to Unity and porting to Unity is the exact same thing mmmkay. Because Unity's support for VB is shit at best; Meaning that VB will need to be scripted into Unity, you kids will end up having to reprogram the entire game in C#.
You guys still haven't made a concrete decision on what engine to go with which is extremely important. In your reddit thread promoting the game, Seth claims that a new custom engine is being worked on, well that would mean that the move to Unity isn't going to take place. Make up your goddamn minds.
If you guys plan to have the game in multiple engines, that's an even worse plan because you'd have to duplicate added content into each different engine. You guys have to start putting in some serious and well informed thought into the moves you make, before you make them.
For your viewing pleasure, here is an exact representation of the choices you guys have been making regarding the technical aspects of game development thus far.