The Resistance (most straightforward). Avoid The Initiative and Protectorate.

The "Global Research" pool (the one all factions share) now progresses 15% faster in the early game, but slows down by 20% in the late game. This means you will unlock interplanetary probes by 2026, but the final jump drives (Daedalus, Antimatter) will require a massive endgame infrastructure push. This pacing change makes the mid-game (2030-2040) the most exciting window for total war.