I'd like to be able to tag users in my posts and have your platform confirm I'm using the right user tag before it posts. This functionality was available in Hootsuite, for instance.
I have changed the title a bit and specified it for Twitter. There are separate feature requests for LinkedIn tagging. Please refer to that for the status update: roadmap.socialbu.com/b/feature-requests/linkedin-post-tagging/
Twitter tagging with search is live now. Soon, we will make LinkedIn tagging with search live.