Well I have sussed one thing out. To Export you don't, it is saved with the PLN or Teamshare file, so from the PLN/TW point the Import button at the File you want to import it from and voila!
AC versions 3.41 to 25 (UKI Full 5005).
Using AC25 5005 UKI FULL
Mac OSX 10.15.7 (19G2021) Mac Pro-2013 32gbRam AMD FirePro D500 3072 MB graphics