This is aimed at the collectors. We can currently sort by card number after filtering by release. So I can filter down to GRN release, and then sort by card number. But to see each card number, I have to hover over the details. This makes it hard to look and see which cards in a collection you're missing. Ideally this information would be shown already without having to hover. Maybe this can be added by the user depending on their needs, so it doesn't clutter the mobile view by default.

Maybe even having a collector tool, such as the deck tool, that shows what you're missing, etc.