People are already doing this though. If you are a historian, you are already having spaced repetition on your subject of interest, since every book you pick up from the field will cite the seminal information everyone knows in the field. You are constantly being refreshed on it. Likewise in physics or math, if you specialize in some niche, you are constantly reviewing the groundwork and in all likelihood reading a good deal of review articles as well. That being said, there's no point in the professor of history reviewing their calculus from undergrad, and there's no point in the physics researcher to review all the central dates and names of world history every few years. If you strive to have the breadth of an ocean you won't have time for much depth. There's just a finite amount of information one can intake a day.