It would be so awesome to have a filter similar to what is added now for 'Price' and 'Editions', but instead, it would be 'Quantity Owned' and would show you the total amount of editions you hold as a collector.
At the moment, it is incredibly difficult to find duplicate owned NFTs as you have to open each one to see how many editions you currently hold.
If this filter was included, I would be able to put 2 - 5 and see all of the NFTs that I hold more than 1 edition of.
I like this idea of sort/filter and would like to add to it an idea to put a number owned in the bottom corner of the thumbnail. That way you wouldn't even have to click on it. whether you are on your own collection or on someone else's page.