There's no demo yet, right ? Do the camera controls allow for some pseudo-Hor+ in zoomed in views ?
You could try 1920x800 or anything wider than 16:9, and if it's as Vert- as the rest, chances are TripleHead is.
The camera zooms out so far that Vet- in 16:9 is not really an issue, but at WTH resolutions I obviously can't say how big an issue it becomes.
I'll try adding some other custome resolutions when I do the report, but someone will need to test and post WTH info before we know how much the Vert- effects gameplay at that width.
Unless Demigod stops the Vert- at some point.