Will you be able to get the slots far enough apart to keep from them running together? The width of the woodruff key will likely be more than just a few degrees based on the hole diameter. I don't recall what the hole diameter is, but it's not huge. Say for a 1-1/2" diameter hole, a 3/16" woodruff key would take up about 14 degrees, and you'd need to offset moer than the width of the key to have a distinct slot (not overlapping.) That seems like a lot of shift in cam timing. You may have to cut additional keyways in the cam to get less than 14 degrees, offsetting both the new key slot and the keyway on the cam. That 1-1/2" diameter guess is probably large, and for a smaller diameter, the key would take up more degrees of angle.
