Okay, I discovered something weird. Using JokeJujitsu's unlockables table, I extracted a fresh unlockables.xtbl and edited the top level superpowers with his new values and the DFA nuke is still gone. I guess this must be the way the engine is made as I wasn't putting in any more superpowers slots, merely editing the top levels of existing ones. I was just seeing if it would work and it kind of surprised me to see the nuke gone still.