So I finally got around to working on a dvd-order metadata agent.
This is for those tv shows that appear in a different order on the DVD than they were originally aired in. This agent should not be used as your primary agent for a section (unless of course you have a section consisting ONLY of stuff in dvd order).
Instead, use this agent on a per-series basis, using the "match using" setting.
[attachment=5108:pic - match using.jpg]
Then the episode information is read in as:
[attachment=5109:pic - firefly.png]
That much was really easy. The part that I'm really proud of is the way it handles DVD-order episodes that consist of multiple Aired-Order episodes:
[attachment=5110:pic - invader zim.jpeg]
No guarantees that this won't crash, explode, or otherwise fail to perform as expected, so feel free to post bugs here. 
Updated: now will work with episodes that don't have a DVD order set, like current seasons, or specials.
So enjoy, and let me know how well it works for you![attachment=5111:DVDorder.bundle.zip]
[attachment=5214:DVDorder.bundle.zip]
[attachment=5714:DVDorder.plexapp]
Updated version:
https://forums.plex.tv/topic/21141-dvd-order-agent/?p=626550