Better approve procedure
Have a link to approve a comment that doesn't need the moderator to be logged in TYPO3 backend.
As examples take EXT:login that allows an user to recover password or EXT:femanager that allows an user to confirm account creation with a simple link sent via e-mail. The link has a token to secure it.
Actually, the link sent via e-mail to the backend doesn't work at least with TYPO3 7.6, see also issue #72500