One really BIG idea:
a) With every evolution not only slots count is increasing, but also size of the Cogmind. So, it will become 2x2 like behemoth at -9, than 3x3 like borebot... and something like 10x10 at the end of the game. Player should quickly find a good launcher or swords or something else to force their way to stairs, becaue Cogmind quickly will become too large to go through most of the corridors.
Also every time when Cogmind increases it's size, it more effectively crashes enemies (and from some point - items on the ground on which he passed). So if, for example, 5x5 Cogmind steps on the chute trap, he doesn't need to worry about anything because he can compact all compactors in the wastes.
Also big enough Cogmind can take on board allies and carry them like a bus or something like that. Allies are safe in the big Cogmind and enemies can't reach them.
b) Additional ending: if Cogmind reach surface with enough allies on board, they decide to go away from Complex and create a home inside of the Cogmind to live in peace in it. So, Cogmind continues increasing it's size to make life of his inhabitants more comfortable. And then new robots somehow hear about great new home and come to live in it, and it increasing even more to accommodate everyone... At the end it becomes a new Complex - Complex 0b11. So Cogmind surprisingly recognizes that Complex 0b10 and 0b1 are also just the overgrown Cogminds themselfs...
P.S. Amazing thread!