Would there happen to be a plugin that tracks the loot tiers of various monsters, and the drop rate they have for each salvage type? If not, how difficult would this be to create? I have little experience in dealing with Decal programming, so I'd appreciate any info on this.

I'm already working on it. I'm preparing for exams at the moment though, so it's not likely to appear in the next few weeks unfortunately. Some of the results I've see so far have surprised me a little bit- gold shredders for example don't drop anything WS9 or 10. At least I've never seen it happen yet.

Glad to see this worthy project is being worked on. I first noticed how truly useful it would be when I started gathering salvage for a cov suit. No one seems to have any real idea where the best spots for non-imbue salvages are, just vague guesses.