The larger of the two documents strangely reads a little bit like a patent. One of the four authors seems to be involved in patenting. Though it is submitted on Researchgate where one would normally find scientific papers?
Looking at the one author, Mr Langbein, he did submit a paper with some other authors earlier covering many of the graphic elements and the discussion of the Payne #5 concept. This one though reads more like a scientific paper.
The style of writing is so different though that I expect Mr Langbein was not very involved in writing the AKN (the larger) document.