Or modify the deck itself to have a slide out piece of steel that you can bolt/secure into place when you need the extra length. Something like this, but you're only coming out 12".
I might be missing something but could you use ramps at the front of the bed, that old hypotenuse trick?
Like this.
I don't know if that would work for you or not but how about this
https://www.truckpaper.com/listings/trucks/for-sale/26130313/2020-cadet-11-ft
we saw a couple of these out in West Virginia. Talked to one guy who said he really liked it. Pretty expensive I believe. I would worry about being top heavy!?