I dragged a ferry trailer from Dover to Oxford with the suspension still dumped, if that counts? It certainly made a mess of the tyres… 
Being good little subbies, of course, we did the only sensible thing. Tipped it, reloaded it, and shipped the bugger straight back again for someone on the other side to get the blame. 
In my defense, I’d only had my Class 1 a week and didn’t know they dumped the air when they shipped the things - hell, I didn’t know you COULD dump the air, the trailer I’d trained with had been on springs with a ratchet handbrake.
(This was before suspension which raised itself at 15mph, by the way. Either that or the handle was buggered. I’ve no idea. Again, see training trailer details above)