I deal with much the same thing as a Shakespeare scholar. You'd like the works to stand on their own, but there is something to be gained from studying the corpus as it evolved. When I go to perform a play I treat it as if the audience is seeing a brand new work for the first time, but my process is informed by what I know of the other works and the context in which it was written -- including what I know of the author.

It's unfortunate that conspiracy cranks take that up as a power trip rather than a serious way to study the plays themselves. And that there's a countervailing effort (dating back to the author's lifetime) to attribute lots of things to him -- it would be great if Edward III really were by Shakespeare, but the evidence is circumstantial at best. We can study it to see if it informs us in any useful way, but the combination of weak attribution and weak play means we don't get much of anywhere.