I bet the most of you didn't know about those options at all so I'll try to briefly explain some...
We can set a project name for your repository, useful mostly for CIA.vc. In some cases the repository name differs from the CIA.vc project name so it would make sense to specify the right one.
Since CIA.vc notifications are enabled by default for almost all repositories it is also possible to disable CIA.vc notifications for your repository.
We can exclude some files for you to hide those in commit mails (e.g. CIA.vc or gentoo-commits). A good example are "Manifest" files.
If your commits will be send to gentoo-commits AT lists DOT gentoo DOT org and you don't want them to be send to the list anymore then just poke us, we can disable it for you.
We can also add additional mail addresses to where commit mails will be send. (Please request this only for mailinglists or so if you and your teammates want to review your commits)
Last but not least: It is possible to ignore single branches from commit mails, neither CIA.vc notifications nor mails to gentoo-commits or additional specified addresses will be send at all.
The Overlays team can be found in IRC (#gentoo-overlays) or via mail overlays AT gentoo DOT org. Also see Gentoo Overlays Team