The previous official color renderings weren't very clear on this, I always thought the 2 smaller thrusters were an integrated part of the bigger leg thrusters in Fighter mode, and just splits out from it in the X-wing-like & other modes.. With the new underside images, it looks like they actually unfurl out from the belly of the fighter. I am liking the SV-303 design more and more.. But perhaps its a new valk syndrome, same as when the SV-262 was first revealed.