Takes care of your matrix needs from the midgame until mission complete.
Properties:
It can be toggled from researching to producing white matrix once it becomes available.
It also makes a bunch of space warpers, which I find convenient to combine with green science production. It slightly overbuilds green matrix to account for this.
Allows full proliferation.
Initially makes 2/s cubes of each matrix type up to green (or 2.5/s proliferated), but can be scaled up simply by putting more matrix labs on top.
It has a modest 50x80 cell footprint, so it runs roughly from the equator to the first tropic line.