Looks good! Yeah, it’s higher than the axle and any road hazard would have to pass under the wheels. Looks heavy enough to fend off anything that might get chucked into it by the tires
I have 20 inches from the bottom of the floor to bottom of skirt so I built a platform between framing out of 1/8” steel and bolted it on with grade 8 bolts and made a door.
I just added a piece of ceiling sheet metal onto the bottom of the existing door. 16g I think, just about 1/16 of an inch. The section I added just covers the 6" gap below the existing door. It does flap in the wind a bit while driving so I added a little bunjee cord to hold it tight against the body.
To make the whole thing I just cut the existing storage compartment in half, and dropped it down 6" to accomodate the height of the propane tank. I still have tons of clearance underneath.