I think plumbing it before the lift pump will be fine. It just seemed an long way and a lot of fuel line for it to gravity from the tank, all the way forward to the Raycor filter, then all the way back to the lift pump. I mounted my filter on a piece of flat steel that came with a bunch of holes already drilled in it, kind of like a piece of erector set. I cut this down to where it is about a foot long. I then mounted the setup on two holes forward of the loader on the side of the frame where there were already two holes in the frame. On my tractor one hole was open and the other had a bolt and nut in it that held a bracket securing fuel or hydraulic lines to the back side of the frame.
I really wanted to mount mine on the back of the tractor. Up above the three point on the back of the fenders would have been good but it is higher than the fuel tank outlet. There just isn't anyplace except up toward the front of the tractor. Space limitations is probably why the factory went with the poor fuel filters the BX came with.