Get a single korok. That's it.

why not get all of them like in botw? we could also possibly have subcategories for the different regions

I would prefer a certain number. For instance, 10 Korok Seeds, or 20. That way it is a reasonably long challenge.

The fastest korok is straight after purah pad and there's nothing unique about it. Having certain numbers for sure would be great to have again (10, 100, all, all buddy koroks, korok regions).

Definitly a good Idea, but it would be nice as bread said to have a set number, or a category such as all GSI koroks