Variant added as complementary Products in Search and Discovery App

[Anttopham]

Hi All,

We're running Impulse v7.3.4 and Shopify Plus. 

We use the Shopify Search and Discovery App for our search and related product areas and want to use it for complementary products.

https://help.shopify.com/en/manual/online-store/search-and-discovery/product-recommendations#complem...

https://shopify.dev/docs/themes/product-merchandising/recommendations/complementary-products

For the most part, it works perfectly well.

We have some products that pair well with others but only a certain sizes fit (ie: medium). Customers routinely buy the wrong size and it ends up being returned/exchanged. 

So, can I add only the relevant/correct size variant (using variant ID) as a complementary product? And if so, How?

Best wishes,
Anthony