I agree with Nick’s assessment that the theory is ridiculously convoluted, and that it cannot possibly be correct.
The map code is the most difficult of Zodiac’s cryptograms to solve, because only three of its symbols are repeated. With so many unique symbols, numerous solutions can fit into those 32 characters. By itself, a solution to the cryptogram is impossible to validate. But maybe someone can discover some indisputable connection between the map and the code. Keep trying!