Having an M929 and M931, I don't have bumperetts to begin with and on my A3 deuce, they are coming off.
I pull my M1061 with the type of A frame that you talk about and I find myself, when backing and turning tight, wondering if the gusset by the bed is about to snag a tire lug or tire grab an air line or that Ubar on the side of the tongue. Hasn't happened yet, but given time, it will. M1061 will probably be getting an extend(able) tongue.
If you plan for a full 90*, there is a margin of safety.
Google "pup dump trailer" and look at all the images with really long tongue. I think they do that for leverage and stability for heavy loads, but not sure. And it's a whole lot easier making it shorter when starting from a full frame, than making it longer once cut.
Edit...some long tongues are due to weight distribution because of bridge laws...they need the distance. I know Michigan had the extra axle (and other requirements) long before Indiana, so you might want to check out distance between axles. Then again...if it's for a "show truck", it's unlikely to be hauling at maximum, so wouldn't matter.