I do like that document a lot. I would have to agree with you on "what its not" I watch that video a few time for other insights but it doesnt really have any. The first link on your sites seems very useful the second one is nice but seems like a hassle to find your moves on it. I will use the first link though. I try to understand the board thought. I used to split it up into fours and realize like you said the 4x4 is the basic structure with white always being on the bottom left. I also use a device that I say to myself to remember where the pieces are if im having a rough day seeing them.. I think if you youve been doing 4x4 I would try to split up the board into 4s. I used flash cards like your first link but I practiced at the just trying to "BUILD" the board in my head.... I would Also add when your playing games any move you make or your opponent makes say the notation. I think this is a big thing as beginners we fall to do. so when we go to read books or try to do blindfold its harder because the squares have less meaning to us. Theres some other things I could share but this is a long post. I like your document a lot though thanks for sharing.
@Watsonchenney I think your brain has to grow in order to do blindfold and it takes time only reason masters can do It I believe is because they put in hours of training. We are just short cutting it so it seems harder..