Did the author stop and wonder why CO2 was important other than some product manual saying so? CO2, in the blood, has a protective role against reactive oxygen species. Oxygen is itself damaging! You don't need to be artificially enhanced by way of superior atmospheric conditions after 9pm when you should instead be getting ready to sleep.

On top of that, if someone really cared about making their body utilize O2 better they would be outside doing hill repeats to improve their VO2max. Worrying about carbon dioxide being a hindrance is silly, because having perfect air doesn't by itself make your lungs bring O2 into the bloodstream better.

If someone is buying an air quality monitor for life extension purposes they should find one that detects PM2.5 and PM10, and figure out how never to breathe that stuff, daggers for the alveoli.

Furthermore, filtering the air doesn't magically reduce CO2. That's stupid. If the author really wanted to reduce CO2, they would have bought 20 plants and placed them around their house.