Is there a way in SSMS to control or configure these add-ins (enable/disable, install/uninstall)?
Is there an add-in or plug-in manager?
If not, is there another way to review and control them?
An old Stack Overflow question references some registry keys, but they appear to be relevant only to a 2008 version of SSMS. They aren't present on my system. Another answer references some folders, but only one of them exists on my system (ProgramData\Application Data\Microsoft\MSEnvShared\Addins) and it has only one of several installed add-ins (Sentry One Plan Explorer).
Other keywords: addin manager, addon manager, add-on manager, plugin manager, plug-in manager, extension manager