The plugin cookies does not add cookies correct to the server header and does not correct read previous set cookies.
Instead of the correct cookie data a hash ref (i.e. HASH(0x178991c) is use as output.
That's a fault.
Testcase:
Setup a blog with some posts
Add only the plugin cookies
Add only the attached testplugin lastvisit
Open some blog posts in webbrowser
Reload some pages
Recognize that there are cookies, but some are missing or destroyed; most of them have incorrect values or names
testplugin lastvisit