I have two of Ken's 5/16" bolt-on grab hooks on my bucket, plus a third at the back, bolted on the cross-drawbar. Ken's grab hook on the cross-drawbar is always there and handy for 95% of my heavy pulling needs.
When I need (rarely) to drag an oversize log a short distance I pin a Speeco pivoting grab hook to the center drawbar + 3/8" chain. After dragging log free over the ground, I elevate log with OMNI Hanging Tree (pictured) and safely good to go.
I do not leave the Speeco attached to the center drawbar. It pivots, gets under the check chains/stabilizers and will mangle the check chains when you lift the three point hitch. (Ask me how I know.)
Kubota gets a fancy price for their check chain components, which are metric, so you cannot substitute turnbuckle parts from your local hardware store.
Go with Ken's. Save your stabilizers.
Picture below does not show rear Ken's BOGH in detail but it is there, contentedly, back to the camera, in gray primer.