Sure thing knp7765, that would be cool. I like your stealth fighter idea. Yes, my game uses the D12 system - sorry for not mentioning it earlier. Some of my ideas for the Industrial tech tree would be:
Improved Industrial Efficiency 1 - Roll 2 D6 and keep the best result. Add that many IPCs to your hand. (just like the old War Bonds)
(which would lead to)
Improved Industrial Efficiency 2 - Roll 2 D6 and combine the totals. Add that many IPCs to your hand.
Full Build Capacity - Your Minor Industrial Complexes may now be upgraded at no cost. New Minor ICs may be built on ANY territory.
Just a couple of ideas. I’m open to different names for them and so on. I’ll post the rest of the Unit Tech Cards soon.