I’ve never come across the towing law regards higher taxation class,only ever mentioned on here and nobody has ever posted the legislation in black and white.I’d guess not, not legally anyway. There’s the weight issue (the A frame is probably not braked), plus something about towing a higher taxation class with a lower one being a problem too.
Get some long ramps so it can go into a grain trailer and be out of sight.
As posted better in a curtain trailer etc than towing,the correct way with towing it to use a linked brake kit like camper vans have.