I do exactly the same with my tiddly 10kg-ish 2.5hp outboard. It’s not too heavy to lower by hand, but it’s still awkward, needs two people, and presents a risk of dropping it in the sea. Fitting the outboard to the dinghy on the foredeck and then lifting the whole lot overboard with the spinnaker halyard is easier and less risky, especially if there’s a chop, and I can do it on my own although it’s more elegant with help. I don’t have a warping drum on the windlass but the halyard winch is perfectly sufficient for our dinghy and engine.Our outboard is a 35kg Yamaha Enduro 15hp. We dont have a lifting crane. We lift the whole dinghy up the side of the hull just forward of the spreaders. We do it using the Spinnaker halyard either with the rope drum on the windlass or a winch at the mast. We have a three point bridle permanently rigged for this purpose.