Out of curiosity, what do you need 32GB RAM for? Most users who need that quantity, are most likely to be looking at the Ryzen7 lineup (or Threadripper).
You'll find the QVL for tested, working memory kits for the motherboard here:
https://www.asus.com/ca-en/Motherboards/ROG-STRIX-X370-F-GAMING/HelpDesk_QVL/
That board has the option of ECC and non-ECC memory....