The fact that adding in information to support a query at inference time has no guarantee to be limited by that information. Besides my 15 years of natural language processing experience, my first hand experience is non deterministic output using that technique because the math simply requires it to be. I know we only trade in anecdotes because the studies, perhaps considered more rigorous collections of anecdotes, like the BBC studies on summaries show that they cannot summarize only synthesize, so... I guess I mean to say that while I can't rule it out that some day it may be possible, or even that it works for some people in some contexts most of the time, there is no study to point to that shows anything resembling a "solution." Perhaps you meant something like "there is a prevailing technique" not that it is a solved problem.