Keep in mind any energy going out the exhaust (Heat) is an area for recovery of "waste."
I don't need to create anything "extra" to find a gain if all i am doing is minimizing waste.
As for OU from a reactor.
I am a firm believer that it is real, and has come in many forms. HHO (ish), Nitrogen Hydroxide, catalytic reaction, fission, fusion, ....
Some acidental some with controll and some are better than others. The latest reactor that seems to has a OU effect appears to be the Andrea Rossi's E-Cat. I believe Meyers was legit also but was it "HHO", i don't think so.
When you're one step ahead of the crowd you're a genius.
When you're two steps ahead, you're a crackpot."