Moving or creating many product variations
Question 1:
until some awesome person posts a different answer, I'm afraid the answer to this is to use &quot;commerce_bpc&quot; to generate all your variations, and then attach your variations to the product by writing a standalone script.  See below.
Question 2:
you can attach variations to a product after they've been created with &quot;commerce_bpc&quot;.
field_data_field_product is the table that links variations to products.
Adding new rows where &quot;field_product_product_id&quot; is the variation you want to attach to a product will attach the variation to the product.
also,  add the same row to:  field_revision_field_product and clear cache.