Castorama doesn't manage product variations and will create a separate product page for each product variation from your catalogue.
However, to optimize referencing through Google, you must provide to Castorama the parent ID of your variations in the following attribute:
- "Mirakl_ProductGroup_ID": Parent ID of your variations (common reference for all variations of a product). This attribute must be empty if the product has no variants.
Parent products must be excluded from the feed sent to Castorama, if your catalogue contains any.