I’m not sure how this suggestion will help with placing specials among the episodes.
If there’s a custom order supporting the specials/OVAs among the regular seasons, you can already do that (as long as the custom order is available on TVDb). There’s a feature suggestion to also support TMDb release groups.
Edit: there’s also a suggestion to support non-integer season/episode numbers.
Let’s keep this suggestion focused on an option to let users switch between orderings (independent of how the files are organized).
