The cat urine smell is ...

The cat urine smell is probably being caused by free ammonia. CL02 doesn't bind with ammonia and this can be a major issue, as well as nitrification could be occurring. When dosing Chlorine instead of Chlorine dioxide, the chlorine is able to bind with ammonia to form chloramines, might be worth taking this into consideration.

Also, I'm surprised there are no free volatile organic compounds present, as you say the odor complaints are associated with new deco and carpeting. A major source of man-made VOCs are coatings, especially paint and protective coatings.