Can you output Shopify ‘collection’ page results on teh instant search page as well as the products?
You often don’t have that many collections, which is why for us displaying them only in the autocomplete was enough.
Mixing collections with products in the same list wouldn’t be doable. Indeed, the filters are only provided to be used with products, and putting collections there wouldn’t make much sense.
However, displaying collections in another result list / tab / whichever UX you feel is best would be doable.
This is not implemented, and falls out of the scope of what we can provide.
But this could be achieved using custom front-end code.
You could definitely inspire yourself from the code installed in your theme to search in products and use the same logic to have results for your collections.
Here are a few pointers: