'Treat image as' no longer available in metadata?

[Harblar 29]

So, way back I used (and really liked) the coverart plugin, but it was causing issues with emby server locking up and or not displaying art when browsing my movies. When uninstalled everything was fine, so I haven't used it for awhile. I've recentely upgraded my theater for 4k and have managed to rip 10 or so UHD's to mkv and wanted these to be easier to find so I reinstalled the latest version of coverart (which seems to run much better), but I've noticed that all the HD-DVD's I'd previously had tagged as such in the metadata no longer show the appropriate HD-DVD overlays. When I check the item info there is no longer a line to enter in the "Treat Image as" type.

 

How do I go about getting all my HD-DVD's to show as such now? 

[Happy2Play 8296]

Have you seen this topic?

[Harblar 29]

No, I hadn't, but that does explain things. Still seems like one of those, "if it ain't broke, don't fix it" sort of things, but maybe I'm just a tad bitter that I had to spend the last 2-3 hours going through my entire collection and manually retagging all of my VC-1 items (which had all had previously been tagged correctly via "treat image as") 1 by 1 as needed...