I just finished researching T2 orbit defense, and I was disappointed to find that I’d wasted my time. They need 50kMWt power, and cost 25k credits, and 50k beron. And for all of that I get effectively nothing. The damage increases from 1k to 5k, but since anyone actually intent on taking a planet would send a bait ship before the real fleet it really makes no difference.
So, I have an idea to improve the overall value of orbit defense. Instead of having the orbit defense be a single shot at full damage make it multiple shots at 100 damage per hit. This means that for a T1 orbit defense you’d need to send in either 10 bait ships, or something that can soak up 1000 damage. The T2 increases to 5000 damage, so you’d need to absorb 5000 damage. That means that invading a planet defended with a T2 orbit defense would actually be a costly move.