I went to my account page for the first time in quite a while and see there are downloads for Platinum Core Plugins and LANDR. Are these handled by the Command Center or do I have to download and install them separately? The website isn't very clear about it but I don't see them listed in Command Center.

They are separate downloads, but they should appear in CCC.
 
They can of course be downloaded from your account and installed manually.

The core plug-in installer is automatically downloaded and installed by the Command Center when installing SONAR. LANDR is installed if you elect to use the LANDR export option. No additional action is needed to get these features when using the Command Center.

Thanks for the replies. Having separate downloads listed for the Core Plugins, LANDR and Platinum is a bit confusing since no other downloads are mentioned in the "Available Downloads" menu. Core Plugins and LANDR are not mentioned in my Command Center list. I'm glad I don't need to be concerned since I rarely go to my account page and would miss any notifications posted there.