That is a good recipe. If he is careful which it sounds like he is he will easily get 4 + cord with a chain.
You can cut 4 + cord without ever sharpening, assuming you don't hit anything and don't drop it in the dirt? Maybe I am underestimating the chain or underestimating the amount of cuts it would take to get 4 cord. I suppose it could be done but not sure I would want to let a chain go that long before i touch it up. I like sharp cutting chains.