CO2 while occupied is generally under 750; I'd prefer to keep it under 700 but we also balance that with energy efficiency for that make-up air; I don't have an ERV, so we suffer a little there.
(We don't live by a freeway but - (a) Pittsburgh's air isn't great; and (b) the canadian wildfires were pretty bad here at times this summer, and that was what caused that 0.8 ug/m^3 pm2.5 spike).
We have, um, a lot of air filters left over from covid, though, so we're a little spoiled in terms of being able to manage AQI easily.