To reiterate what has been said when this type of question has arisen in the past:
Just because we don't have a specific forum for a distribution, that shouldn't stop you from posting a question about that distribution. Often, a problem isn't specific to that distribution and so any of us can provide you with an answer. At the time of writing this, we have 110,977 members and so the chances are that someone is running the same distro as you.
It is rare for a question to go unanswered or for the answers to be unable to point you in the right direction.
We have a large number of Gentoo users on LQ, so feel free to post a question - whether in the Linux-Distribution forum or in any of the other forums.