[petsfed]

"There's also altitude compensation but unless you're doing something really weird that shouldn't affect you so much."

Disagree. I've moved co2 sensors between sea level and 2000m, and measured reference 400ppm gas and seen quite large differences (~150ppm). So it can matter. That's the reason why the SCD30 allows you to set an altitude or pressure.

But its not important enough to constantly feed it pressure data, a once-a-day pressure reading from the NWS would be sufficient.