This forum is running the best tech currently available. Xenforo is the #1 forum software at this point. The issue with the 3 letter search term is actually a MySql database limitation, and yes, it is annoying but there isn't much that can be done about it at this point. The alternative is to use Google with "site:5thgenrams.com" after the search phrase.
I don't know squat about the back-ends of websites, but 5thgenrams has the smoothest, most sophisticated, most enjoyable forum capability I've ever used. So my hat is off to whoever is figuring all that out and maintaining it.
I do agree that searches even within 5thgenrams do leave something to be desired. Oddly, when I've used the internal search and couldn't find the thread I
know is there, I open a new browser window using DuckDuckGo ("DDG"), type my search term along with "5thgenrams" into DDG's search bar, and I usually find exactly what I'm looking for that way. This particular "failing" is NOT exclusive to 5thgenrams, I almost never have any luck using any internal search on any website.
Regarding a way to slow down redundant proliferation of existing thread topics, would it be possible to generate a user-interface routine so that when anyone wants to start a new thread, they first have to go through a set of set of pull-downs that define & refine the category, which itself then shows a listing of the threads that already exist on that topic, and before a person can actually begin a new thread, they have to click a button at the end of that "existing threads on this topic" list, in order to get to the actual window that lets them post a new thread? Again, I have no idea if this is possible or practical, I just toss the idea out there in case someone who designs websites can consider if that approach would be (a) possible, and (b) effective.