I find it hard to believe that the printer will remain accurate to sub-millimetre distances over the full range of printing an A4 (210 mm x 297 mm) page. If there is a moderate amount of black on the page it will have to travel a considerable distance - maintaining accuracy over those distances is hard, and I'd love to see some evidence that they've been able to do that.
There is no hint of how the feedback will work of where it is on the page. So colour me dubious. Having said that, I'd love for this to succeed. I just hope they're cleverer than I am.