The word “unstable” here means that it is not from the official openSUSE repos. As you can see there, several versions are packaged by several individual persons. You have to trust them (as allways).
But it might be better to disable to the repo after installation of the product (Yast > Software > Software Repository, select the entry and uncheck the Enabled box below for it).
You can then have no problems with eventual other software on that repo. When you think you should upgrade from that repo, then temporary re-enable it.