Allows changing per-page settings, and adds a easily accessible
"page control" action link below every page.

You can use this to immediately change per-page flags (_READONLY,
_HTML, _DISABLED and so on). Or you can delete a unwanted page as
soon as you discover it.
It also enables you to edit any entries in the {meta} field of
database entries (which sometimes contain HTTP headers, or page
"class" settings).
And the fourth possible action is to easily rename the page (with
letting ewiki adjust all links to it without further intervention).
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You cannot modify the README.plugins file, but anyhow any ideas or suggestion should as usually get filed on BugReports, UserSuggestions or even better the README.plugins.Discussion.