That's an interesting tender! I bet she moves right along. Do the dogs ride in the cavities on each side of the small cooler?
I don't have a davit but have considered installing a small removable one for light loads like an outboard motor. I envisioned mounting it in a pipe extending below the deck to the hull on the port side where my rail gate is located. It would slip into the receiving pipe and have a manual crank on a block and tackle to provide the mechanical advantage.
I never envisioned lifting something as heavy as 500 lbs, though. Maybe 150-200 lbs max. Where would you store the tender, in the cockpit? On the transom step? If you used a bow crane, I guess you'd have to store it on the bow, obscuring your lower helm visibility and blocking the hatch from opening.
My 15 inch tube Achilles inflatable stores on bow chocks but is low enough in profile to allow me to see over it from the lower helm. It light enough to lift it over the rail from the dock and slide it into position on the bow.