You can use either the hand method or electric starter. Magneto ignitions do not need to be flipped fast, it's all in setting the prop correctly.

I have 2 different fuji's that start with nice easy flips that are on magneto's. My 2 G26's were both on mags before I had them converted (to save weight) and both took nice easy flips

There is only one engine that comes to mind that needs a fast flip and that is a DA engine. The ignition is set to only fire on starting at a certain rpm or higher.