Hello TravelingGeeks,
You might consider mounting the base of the "L" supports on the underside of the bumper since the plates on top of the bumper and bolts between the coach and bumper would not need as much space. You then may be able to slide the ends of the "L" bracket a little more under the coach. Even though the tote is lightweight the bulk of its load would rest on the bumper. You would probably need to buy cap nuts to cover the ends of the bolts that would be sticking up or find some rubber gromets or feet to place over the bolt ends, as you would not want to wear holes in the tote from the bolts. We use two additional straps that go around the bumper as a safety precaution. Additionally, we have a lightweight aluminum ladder that sets between the tote and coach. Attached are some photos of our setup on our 2021 Mallard M260 the tote is the Camco Rhino Tote Tank, 21 Gallon. We have 14,000 miles with this setup. Check it every stop for fuel, breaks, and stays looking for any fatigue cracks or strap wear. We have replaced the straps due to sun exposure.