How do you display legacy extensions?

When a new version of macOS is released there are always sites that encourage people to report which apps work properly and which ones don’t. So when it comes time to upgrade a smart user will research to see what apps may have problems and whether or not the developer has a compatible update coming soon.

So far as I know, you can't. Concerning Apple’s announcement regarding Legacy System Extensions, there is nothing we have to do or be worried about at this time. What Apple is telling us is that when the next new operating system comes out (Big Sur), it will no longer allow those Legacy System Extensions which are part of other vendor’s apps. That means that any software vendors who have failed to update their offerings will be incompatible with the new OS. Those vendors have all been told what changes they will need to make to be compatible and I assume they are doing so. The bottom line is this. Before installing the next OS we need to visit our vendor web sites to verify that they have updated their offerings. If an important software has not been upgraded, then it might be a good idea to wait before installing Big Sur. 

CaptainBly wrote:

How do you display legacy extensions?

Hold down the Option key, click on the icon at the top left of your display and select System information. Now look down the list to the Software->Extensions menu item and select it. It will take few seconds to display. Now click on the Obtained From column to sort the list. Anything not obtained from Apple is a legacy extension. These third party extensions are located in the /Library/Extensions folder.

But Ronasara’s advice is good as gold. You don't need to do anything right now. This is all in preparation for the next version of macOS and how it will handle extensions. Developers who value their customers will have updated their apps in time for the new macOS

Thank you so much.