I'll be watching this thread because my first thought is you're looking for a unicorn. 😜
There *are* machines that are multi-thread; you can actually sew with 2 threads, threaded through 2 needles, at the same time. But they don't take individual stitches. I'm not sure what purpose that would serve?
My longarm dealer is in his late 60's and has been selling and repairing sewing machines since he was 10. Do you have someone in your area like this? I bet he/she might have an answer.