As stated below, I forwarded your question to the BANA TG Committee and received the following response from the chair, Aquinas Pather:
Here are some thoughts and suggestions to try and answer this question. I did not know where to start either, so I tried to see what some of the challeges are when actually doing the tactile:
1. It is clear that this cartogram shows the population density in a graphic form with a scale, namely that one square represents 100,000 people. Therefore the tactile must be able to show that relation
2. I do not think that the colours on the tactile will be helpful as there are so many, and the fact that the individual states are labelled, they could be identified with the alphabetic keys rather than by colour/texture. [I would suggest that a TN be added saying that the colours are omitted]
3. It would be nice to show both land and water, but in this case it seems prudent NOT to texture the water because of the labelling that is required.
Most of the labels need to be "outside" the map because the reader needs to be able to count the number of squares and the labels will interfer tactually. [I used lead-lines in some cases]
4. The inset map that shows the actual states should be included.--I was trying the find a good reason to omit it, however, this map give the reader the ability to compare the actual relative sizes of the states with those on the cartogram. It is clear that all the states cannot be labelled--I thought that only the ones that are keyed on the cartogram should be keyed on the inset map.--Otherwise the map will have to be divided in the same fashion that we did in the USA Example
5. I made an attempt at the first cartogram just to see how the elements would fit--See attached PDF--The second cartogram may have to be split into two as it seems to have more information than the first. You will notice that I included some of the braille--not sure of the formatting. I also did not place the two maps on facing pages.
Any way; This is a tough one. Maybe others could add or subtract from what I have shown.