Flawed design for urban as PM reading needs fan running for 30s to have good readings

[zakna]

Reading the specifications for the PMSA003I particulate matter sensor (datasheet)

It seems to have stable reading u need to wait for 30s

4. Stable data should be got at least 30 seconds after the sensor wakeup
   from the sleep mode because of the fan’s performance.

By default the sensor in urban.py wait for 5 seconds which gives erratic readings.
I tried with a 30s wait and it gave much more stable readings but then i have to operate from usb because this will drain the batteries very fast, defeating the whole concept of the device...