Good news Weltall, I figured it out. When I looked at the station generation code for the original TUP months ago, I noticed that Neutrino's world gen code was the only mod code I could find that resembled it and ended up using it as a reference to get the old code working. The problem is that I used the same name ("CorvusAddon") that Neutrino uses, so if both mods are running at the same time the TUP Corvus generation code will get run twice which creates two Scrapyards right on top of each other (and incidentally Neutrino's Corvus generation code won't get run at all, so the Neutrino solar powerplant won't appear in Corvus). Long story short, I would have saved myself a lot of trouble if I rewrote this instead of trying to shoehorn in the existing code. Renaming CorvusAddon solved the problem for now.TUP V7e fixed
Some other modders have been giving me advice and I think long-term I will add a couple of new star systems and move the Scrapyard to one of those. The Scavengers being in Corvus is a holdover from the days when Corvus was the only system in the game. Erick Doe wrote In Aurora's Shadow
which provides a nice backstory for the Iota system where the TUP standalone missions take place. Perhaps Iota will be implemented in the main campaign in the future.