I don't know about Clay Dot, I've also heard about the similarities with Clays.
But personally, I would never load Clays for major. I'm sure OAL plays a factor, but I have a great powder for major.
My Clays minor load is 3.0gr of Clays under a 180gr plated. I use the same for fmj and prefer fmj. But club matches and practice days get plated stuff loaded. Plated and coated lead I consider identical.