So this has been going on for somtime but I've just now decided to post here in hopes that AMD Matt can pass this on for a driver patch.
Star Wars Battlefront, Vanilla maps run smooth as butter, dual 390x's 4k ultra settings, but in the expansions ( Outer Rim, Bespin, Death Star) the Microstutter, Ghosting, Hitching and low framerate with Dual GPU's make it unplayable. Disabling one 390'x or playing those expansions in windowed mode eliminate the problem but then we cant take advantage of crossfire performance.
I've also created a case/ticket with EA games with the same info just in case but considering the game runs fine without crossfire it would seem this is an AMD driver issue. I've also noticed that it has been a long time since any of the AMD drivers updates mentioned anything about Star Wars Battlefront.