My 912uls is installed in a Kitfox SS7. I chose to go without an electric aux. pump, just gravity flow and the Rotax mechanical pump. This is very common in Kitfoxes. I now have 420 hours on this airplane with no problems at all. My fuel pressure does sometimes go to about 2 psi during WOT climbout at max angle Vx with low fuel in the tanks, but the engine has never hiccuped even once, so I quit being concerned about it. I have no check valve around the mech pump (a check valve around the engine pump is unheard of to me in the Kitfox community).
