You will completely change the operation of your implement by making it a ridgid thing mounted to a framework like that.
You might like the mobility, but I think you will not like the operation of it any more.
Harrows are meant to flex & flow & move around some. Follow the ground, not be mounted ridgidly.
Buy a carryall like you picture, and hang the harrow below on chains. Then it will still work like a harrow.
I'm not sure on why a person can't turn on the ends with a harrow? You just need a long enough chain/ rods/ hitch so the tractor can turn. The harrow will follow & come back down the next pass behind you.
-->Paul