I'm not sure if this helps the OP or not, but here are some pictures of my 29.5 BHDS hooked up to the B&W OEM Companion Hitch set all the way back in the 6.75' bed of my '11 F350. I obviously still have a little room to go, but the trailer axles were pretty torqued and I was on pavement so I didn't want to push it. If you zoom in on the wheels, you can see how torqued the axles were.
I have the Reese Revolution/ Sidewinder pin box, I just haven't set it up to pivot at the trailer yet, so this is what you get from a standard pinbox that swivels at the hitch. Looks like I made the right decision on the Revolution pinbox. And yes, per B&W, you can use this pinbox with the OEM Companion, just not the original companion with the single attachment point.
I considered a sliding fifth wheel hitch, but the OEM Companion/ Revolution setup makes for an easier switch to a useable truck bed. Not lightweight like the Anderson, mind you, but still easily removable by one person.
The Anderson Hitch was pretty appealing too, I just worry about the lean of the trailer going around corners. That is an issue for my buddy who uses a gooseneck conversion.