We have a number of operating units that have been using TeamCity to build their projects, but each has their own server. We're planning to move all of the other units onto TC from Jenkins and consolidate all units' builds onto a single TeamCity server. The only documentation I've been able to find for merging servers is about five years old, and the data model seems to have changed significantly since then.
I noticed that the documentation states that moving one project from one server to another is not supported. What is the best method for merging multiple TeamCity servers into a single, central server with a lot of agents?