To me it doesn't matter how many pixels the DMD has in total.
Even if the input signal is 1080, whereof the "WXGA" DMD only can display 912 pixel of a 1920 pix line. In that case that's less than the half.
So it makes no sense to me, to have a great native y resolution (1140 mirrors) what's much more then needed for 720p/1080p, but with a huge missing number of x resolution mirrors.
Just only a few days ago, I could test a Luxcine C7 with that 912x1140 DMD. In the options menu I could select between "16:9", "16:10", "just scan", and a few others.
With "just scan", the result was as expected - the film picture was cropped on left + right side because of the lower native x resolution. With 16:9 the picture was horizontally cot cropped, but pixel compressed.
Anyway ... I'm still confused.
Thought, early UHP 720p DLP projectors did have a real nativ 1280x720 DLP chip ... but I can't find any datasheet on ti.com.