Never had the courage to do this, but in the past have stoned small grooves and scuffs from cam lobes.
Back in the day, Ford Pinto engines suffered from cam and follower wear. The followers always wore more, and if you were aware of a problem, it was an easy fix if you caught it early. The expensive cure was a new cam and followers, but for European Engines the cam came out through the back of the head, so it was head off, or engine out, or a hole in the bulkhead. The cheapskate cure was a new set of followers and removal of the wear ridges by hand stoning the cam in situ. A new, clean and free flowing oil supply rail completed the job, and you were back on the road for a good while. The design was different for US motors, the cam came out through the front.
The performance difference after this codge was marginal, but the motors were restored to smooth unobtrusive running, even for a Ford. Remember these were real cheap clunkers, by the time I got them, and a noisy cam was a good bargaining chip when negotiating the deal.
The metallurgy was fine, failure was all down to extended oil changes and blocking of the oil supply rail with carbonised oil.
Wear starts as straight line across the follower, as the greatest load is always concentrated in one place. Once through the hardening, its like a pothole....clunk clunk, getting bigger and deeper. On the cam, the contact load is spread over a larger area and maximum load only occurs on the toe for a short time in comparison, hence the differing rates of wear.
I do not know if cams and followers are hardened to identical standards..any cam grinders on the forum?
Swarfy