Forgot that i'd used my gmail account (which i rarely check) for reply notification.
I was wrong, the DVI input isnt set to 1:1, its set as Aspect (selection of: Full, Aspect & 1:1).
Full seems to just stretch it across the width (but not at the 16:9 ratio). 1:1 makes it marginally smaller, 10% maybe.
The re-ordering problem im used to, but usually its only older stuff when 800x600 and 1024x768 were the norm.
I'll send an email through that form, its worth a try. I suspect the market of customers with multiple screens isnt that significant, though its the surprise that it limits itself at a display ratio which i cant imagine has ever held much of a market share. If it stopped at 1920x1080 i could see the logic in that few monitors go outside that, and its surely the most common being bought now and has a fair few years life in it holding a large share.
If the game generated the black border, that wouldnt be terrible, if it upscaled or stretched it (to ratio) it would probably be better.
edit: now ive gone to where i thought would be a form, i see why its 1280x720