Continued Excessive dust in home air
The biggest culprit is likely environmental: your dry Colorado mountain air and low humidity. We have the same problem south of you in New Mexico. Raising your interior humidity will help a lot. There are several approaches, ranging from using a humidifier constantly (cheap up front, expensive to run over time) to sealing your house up airtight and using an ERV system to bring in fresh air and exhaust house air (expensive up front, cheap to run over time).

Electrostatic filters and air purifiers will help too, and falls into the category of "expensive to run over time." High maintenance, too.

Another possibility is that the contractor didn't do a very good job with the attic floor air sealing and the dust from the cellulose (it is basically dust, after all) is making it into the house. Likely entrance methods:


Poorly-air-sealed can lights and ceiling electrical/light boxes
Poorly-air-sealed pull-down attic hatches
Poorly-sealed ductwork and registers in the attic, if any
Poorly-air-sealed bath fans and their ductwork
Gaps around chimneys and flues that penetrate the ceiling and roof
Giant stupid egregious holes that should not be there (you might be surprised)