I agree that most (if not all) pros don't decide which stroke they will use. Since so many pros do drop the elbow, and very few have ever received formal instruction. It only makes sense that people believe the elbow drop to be the most natural way of stroking.
I disagree slightly with your last statement. If the Digicue, or any other device, can provide an accurate measure of one's stroke and provide instant feedback on what's wrong. Why wouldn't someone, regardless of how good they are, at least consider making a few changes? Of course, I am assuming that a good Digicue rating always correlates with a good stroke.
Little tweaks here and there I can understand. I was mainly saying that no good player is going scrap his stroke or make major changes to it just because the Digicue points out a flaw.
We all have our own form/style, and if you've ever put at solid 4 or 5 pack on an opponent, or if you frequently run 50 or more balls playing straight pool, I'd say your stroke is fine, regardless of whatever any digital device or certified instructor points out. At that level it seems to be mental blocks that we must overcome, not stroke flaws.
If you can consistently strike the cb within 1mm of where you intend to strike it, you have a pro-level stroke. Unfortunately, that doesn't mean your psr, foot placement, shot/body alignment, thought process, etc...are pro-level.