A lot depends on the General Contractor and the caliber of his subcontractors. No amount of regulations mean much when unskilled or careless people are doing the work. Arizona is notorious for some of the worst construction quality imaginable, and it's worse here in the rural areas.
Good that your duct work was done well, Glort. Be glad you have some standards.
I'm not a fan of blown cellulose; the borate and chemically treated reprocessed newsprint has caused a lot of illness- usually when return ducts have cracks or leaks and borate/newsprint dust gets in the air. It hasn't been a product well tolerated by people with chemical injuries.
Air Crete is an interesting product but our regional licensee botched so many jobs that he's only been used on one disabled housing project I was volunteering on. I had to go over his head to the licensing company to get him to do the job right; magnesium oxide cement is VERY fussy about temperature. He'd been sued and lost several times, but yet he still was about to blow aircrete in an unheated home in the winter, at 4000 feet elevation with no front door. If the cement to water to phosphate mix is wrong or the temperature too hot or cold, you get either goopy soup that stays wet and ruins all the drywall, or dusty powder that gets everywhere and doesn't insulate.
I helped have some specially made pure glass fiber insulation made for homes for people with chemical injuries. Alas, both companies said never again, as without the silicones and mineral oil, their bagging equipment wouldn't work and it all had to be bagged by hand. One burp of their equipment made an entire 50 foot semi trailer full.
Two truck loads of the compressed bales did do a half dozen homes.