bumping this thread with an update and a question.
So I ordered 4x Optoma Laser ST projectors (new ones aime at the golf sim market)
I have access to a Seada 4K pro video wall controller to split the image into 4. It doesn't handle edge blending, but has facility to overlap screens, so I will make a blended edge in my output video.
BUT. I just discovered an old MacPro 2012 for sale. running High Sierra. Specs say it can output 6 video streams. So I could potentially do all the mapping and edge blending in Isadora. Do you think it could handle splitting a 4K 30fps video into 4x HD?