I agree that these are edits that aren't needed. Adding the
<kbd> tag is pretty unnecessary. If you run across this and you think that the edits don't offer any sort of improvement, then reject the edit or reject and edit to improve the posts further.
If you think that something else might need to be done aka a moderator needs to be involved here, then find one of the users posts, use a custom "other" flag, explain what is happening and provide some examples. We'll take a look and step in if needed.