Using the rope sheave as a puller on a stubborn flywheel usually results in a broken rope sheave. A three screw flywheel puller with schedule eight bolts is the way to go. The factory puller uses shoulder bolts which ensures all are in at the same depth so the pull will be centered on the crankshaft but still will not go deep enough to damage the coil. I add a locking nut to my bolts to mimic the factory bolts
There should be end play in the crankshaft. Lifting the flywheel should Allow the shock of the hammer blow loosen the flywheel without crushing the crankshaft. In extreme cases heat is used to expand the hub. It sounds like you are doing all the right things. It goes without saying that a gear puller which hooks to the outer edges of the flywheel should NEVER be used on a flywheel. All I can add is be patient . . . . . 😀
