Zapping magnets does not increase the magnets strength or "magnetism" but makes them more efficient by aligning the grains/poles correctly. Replacing the ceramic motor magnets with a rare earth type would increase the magnet strength but then the stock wiring of the arm and its small window couldn't handle it. You would have to go with a hotter winding.
Wrapping a 'flux' around the motor is one way but replacing those little 380 motors is the key. Then if you're not happy do some pinion swapping... but you will have to elongate the motor mounts some to make up for the pinion diameter.
Let us know what you did!
Jeff