as this may/may not be a good idea, it will likely not happen, jstarkey doesn't like hacking the vBulletin much more than he has to, and from what i've seen of the code, it is kinda messy in some respects, and a pain to work through
also, when are you having problems using the mark resolved links, jstarkey was fixing some of these like the last week or two as i was noticing that it didn't work in all spots, like would work if you just read the post and click it, but if you just posted, you wouldn't be able to click it, if you click the anchor(go to last post on thread), it wouldn't work, etc... but those problems have all been fixed, as far as i can tell when i use it
and regardless what we do, we will never be able to "force" someone to use the link, and just because the thread is old doesn't mean it is resolved
all us mods have been trying to keep up with the threads, if we believe beyond a doubt that the thread is resolved, we can mark it so, but only the thread starter or a mod can do so