The unofficial start of the Mosaic project was the development of the new Roon module that dCS released in early 2019 so it’s safe to say that you’ve been benefiting from Mosaic for months.
When Mosaic Control was conceived, a requirement was that it be possible to switch between Roon (library management, playback) and Mosaic Control (settings management) with as little disruption as possible. That means that you can launch Mosaic Control and navigate to the dCS Processing Platform settings page (upsampling, filters, and mappers), use Roon for playback, and then go back to Mosaic Control at any time in the future and have the settings page instantly available.