Bedlam,
I'm recalling a toy hauler trailer which had to add an axle. IIRC, engineer design spec was too low. I believe this is why Nu-Wa went with a tandem option along with 3 axles scrub too much and from what I've heard are a PITA to tow with. Warrior brand or something with warrior in it..
MH with issues, Tiffin based on Dick and Sandy's issue would be my swag there. They had initially engineer and tire patch issues.
I got in trouble once with an equipment trailer. Asked for 5000 lb capacity, got a trailer with two 2500 lb axles, put my case skid steer on it. Tire the thing to threads. Learned real quick not to trust advertised spec after that!
Marty