So, a lot of things seem to work, just 3 warnings from google:
1: aggreagreRating, so I set this to WordPress ratings (reviews). I have no reviews yet on my products, so I guess this will come
2: review , this one is also set to WordPress ratings (reviews). As I don’t have any reviews yet, this will probably solve itself.
3: no text, just an orange warning sign with no label next to it, which says “a general ID for this product (like isbn, mpn or gtin) Is missing. Check the documentation for a valid ID.
So that last point bothers me, I’ve tried setting the gtin13 to this, as well as the SKU, but this does not seem to resolve itself.
And the last question: some other plugins also create some schema.org fields in my product pages, is that a concern (they are listed twice, on the google tool, first “organisation”, then “breadcrumblist”, then “itemlist” and then “product”. When you click on “product”, it shows 2 times the same information). I don’t know if that is a concern 🙂 ?