Funny you mention AoE. I strongly suspect they drew most of their inspiration from a GT pack, which very much does have delineated tiers or Ages.Its funny you should say that; as I was looking through the mod list I found myself thinking that it actually looks really interesting, and quite up my alley! I'm not sure I've got the patience for super grind and hardness, but if its around the same sort of level as Age of Engineering I reckon I could get on board with it!
EDIT: With the magic integrated too, it also sounds a bit like All The Mods: Expert, but hopefully at least a bit less entangled in its tech and magic progression
EDIT, the second: One quick question - what is the driving force behind progression? Is there any form of ages or quest to follow like Age of Engineering, or is it simply self driven like All The Mods: Expert, where it seems to basically be "what do I want to make? OK, how do I make that? OK, how do I make THAT, to make the first thing?" and so on?
I'd probably call Tier3 Fusion the end-game. And, just for irony, I've never reached any fusion tier in Infitech2.