I did a bunch more hacking on my ESP32 sensor reader code today, deployed the new BME280 into "production" outside, and got my Grafana dashboards updated! And I was able to do it completely successfully without needing to actually plug the ESP32s into my computer to update anything, the remote-updating code worked a treat.
The new sensor is remarkably close to what the Bureau of Meteorology is reporting: the sensor says it's 17.5˚C, 95% humidity, dew point of 16.6˚C and atmospheric pressure of 1017hPa, versus the BoM that says the temperature is 17.8˚C, 94% humidity, dew point of 16.8˚C, and atmospheric pressure of 1019hPa.