I had a short bed truck with an 8ft camper on it and I had the tongue on my horse trailer extended 2ft. I drove that rig for several years and thousands of miles. That was in the early 70's The only reason I sold it was when we got married and consolidated our stuff her truck,camper and horse trailer were all bigger and nicer than mine.
That was in the early 70's and the only plumbing was the sink and fresh water tank. It had no holding tanks to interfere with the hitch.
Well now our current camper is 9 1/2ft with tanks and plumbing hanging lower than the bed.
We didn't like the idea of an extension. We compromised, We have an 18in ball mount and we bought a trailer with an extended tongue. It works great for us.