Looks like a massive project!
Not passing any judgement on this deck but just FYI: Most exterior elevated decks are dangerously built. Substantial change occurred to the IRC requirements several years ago and many contractors and building inspectors are not aware of the changes
Before retirement as a structural engineer, I used to inspect lots of deck failures including a few with fatalities. The requirements are outlined in this document from the AWC. Pages 13 (minimum 6x6 post size and bearing area), 18 (lateral load devices), and 19 (guard post attachment) are the most common deficiencies.
https://awc.org/pdf/codes-standards/publications/dca/AWC-DCA62012-DeckGuide-1405.pdf