Export and save 3rd party plugin settings

No, you can't export them, and there's no import facility for them either. You can do it, but it's a manual process involving saving a copy of your settings folder, reinstalling Audition and then replacing the vanilla settings folder created when you do this, with the one you saved.

Access to the folder the settings isn't quite straightforward either because by default, the folder is hidden - so you have to unhide all the folders on the path to it. On PCs the path is C:\Users\{username}\AppData\Roaming\Adobe\Audition\{version number}, but you can also get to the folder relatively easily by clicking on the 'reveal log files' option in Audition's Help menu. I don't have the Mac path immediately to hand, but you should be able to locate them using the same method - the log files are stored in the folder you want.

If you can identify specifically which settings you want to transfer, it's perfectly possible just to replace individual .xml files - it's just the same process. Ditch the vanilla file, and replace it with your stored one.

Yes I realise that Adobe have never really got this right, but it's been like it forever, and is unlikely to change.