I am currently developing an App which uses the Storefront API (Shopify Buy JS SDK to be specific) to fetch information about collection and products, which works great so far.
Now I would like to mark certain collections as featured or highlighted. After some research I found that metafields might do the job. Unfortunately metafields don't exist for collections in the Storefront API only for products.
Do you have any ideas how to do this without adding another external CMS? I would like to keep in the Shopify eco-system.