It's making the pawl seats and the associated part of the pawl nice and shiny so they run smoothly, and also the tips where they rub against the ratchet. The pawls all being in time is pretty rare, you can tinker with them with a grinder to get them in time if you wish (take the blue seal out of the 'back' of the freewheel and you can see the pawls, then mark them up, reduce their length by a tiny amount, re-fit, and try again, repeat. I did similar with half an Echo and half an ENO a few years back to give 108 EPs, takes a bit of time / effort though!