So, at the first or second map expansion, where you have to deal with a bunch of navy, you are awarded with tech 2 schematics on your ACU(so they say), however, tech 2 isnt even available as an upgrade choice on the commander. Niether is any of the awarded schematics available from factory engineers. In the following map expansion when the north island opens up, tech 2 engineers become available at the t2 air factory. However, i didnt get a chance to actually see what they could build because my com died. But also, i did see that even then, my com still had no more upgrades available. The land and navy factories were still not upgradable to t2 by then either, even though the messages announced I had been awarded with tech 2 schematics in the previous map expansion.
One specific scematic that i recall getting was the t2 point defense, and I was relieved to hear that as the AI land spam was ridiculous, but when i checked, I still didnt actually have it, there were other t2 schems mentioned at the time but I dont recall them.
The only t2 thing I had at all up to that point was t2 torp bombers, which proved to be rather useless for how much resources I had to dedicate to them, while at the same time, deal with the land spam air spam navy spam, and enemy interceptors shooting down those torp bombers. I was only able to break into the enemy land bases by using my commander, sneaking around the very bottom of the map and breaking their eco I tried to use the same tactic on the northern island, but they had t2 defenses that killed me. Would have been nice if I had t2 myself, as it was pretty much impossible to deal with the AI having t2 and me only have t1 later in the mission.