Our prevowners towed a small SUV on a Stehl dolly with no brakes. They had a very massive, solid, but height adjustable, ball drop.
The COMPLETELY IMPORTANT thing to have, is the diagonal bracing pictured above. Any drop without reinforcement of some kind in that area, is not enough. The steel and/or weld can crystallize and it'll come apart clean as if it'd been sawed.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB