>>14737221I had an easier time introducing the idea of 'not in a giant robot monster' gametime by running Phase 3 with a dedicated team and giving each of the players two members of that team that were 'theirs'. Save some people, see the other side of the giant robot fighting, and generally have a break from the main story while still having a chance to catch plot hooks or move things along.
If your players are flat out refusing to do anything outside their giant doom bots, maybe this isn't the system for them.