Several of the ones I noticed being changed were crags, which could probably more specifically be tagged as natural=cliff, for example.

The other ones which are knolls/rises probably still should be natural=peak if they have a name, since natural=peak is more specific than place=locality. You could add a prominence= tag (https://wiki.openstreetmap.org/wiki/Key:prominence) to them, if the prominence is known and suitably licensed for inclusion in OSM. That could be used to highlight or downplay them in the rendering if needed, in future (I don’t think it affects the rendering at the moment).