I use a splitting maul, as opposed to the splitting axe. For the maul I do not find it needs much sharpening. Just a file to remove burrs keeps it functional for me. I’m not sure if that would be different for a splitting axe. The axe has less mass, but presumably hits the wood at a higher rate so your bite may be a bit less than with the maul, but probably not much. I’d use it until you start noticing it not biting well, then see if a quick file is enough to get it back in shape.