I think it's definitely worth reading parts of Phase 1. I don't think anyone needs to go back to all of it, but you can definitely go back to parts of it and treat it like a series of flashbacks to the Phase 2 you know. I think you can also use a lot of what you like in Phase Two as a guide as to what to go back to. If you like Overlord and the Wrecker characters, you really should read Last Stand, for example. Like Ratchet? The early -ations have a fair bit of him. Similar things can be done for Magnus, the Dinobots, Constructicons, Nova Prime & Galvatron, etc. But I think going back to the very beginning with Infiltration isn't a bad idea. I felt that era was pretty good, and you can then feel your way forward seeing what you like.
