It's fine. Front tire crests the front of the fender and begins it's decent onto the trailer, as the rear tire starts the climb onto the the rear of the trailer. In the future, I may fabricate some lightweight ramps to get it over the hump in the event I lose 4wd or have an issue with the rig.
I love this! I just extended the tongue on my car hauler so I could tow with a camper on back of truck. Never thought about a home built dually axle. I totally approve. I’ve also been using galvanized as a good cheap coating on a couple things. Beats powder cost by 10x