In some ways I think having the gravity fill on the curb side would be a bonus. I usually pull in pretty tight with the left side of the TT to the trees to allow as much room as possible on the site. Mid-week fills with a jerry can are tough when you are climbing through the underbrush to get to the outlet.
Reading this, I had the thought of adding a bypass around the pump to allow the tank to fill from the pressure feed. Then you could have a fill on both sides of the TT. Possibly easier than running the pipe around the outside of the camper and would only take a couple of shutoff's and a foot of pipe (like the HWT bypass).
2011 Jayco X19H (purchased 2015)
2008 Jayco 1007 PUP (purchased new, traded for the X19)
2012 Chev Traverse LT with TP