You’re replacing the complexity of one app with complexity in another app. Adding friction. Basically, you’d have to duplicate DT’s search interface one way or another in KM. Either you have everything that exists in DT in KM, then why would that be “easier” to use (and in what sense?) or it’s incomplete.
In my opinion, you are overengineering it. No one can remember all the search options. Nor all HTML elements with their attributes, nor all CSS selectors with their subtleties. There are things that you need most, and you’ll remember those. For the rest, you can look them up. And if you happen to use one or more of the looked-up operators/prefixes/whatever, you’ll remember them, too.