Bom weather - missing cloud coverage

Pretty sure BoM do not supply such a sensor via their API but you could ask for an enhancement in the github repository’s issues section.

As an alternative source for this sensor you could try the Astroweather integration.

cloud

high
.

A much better option would be to use an actual Lux sensor. As especially in the late morning and evening the sun can reflect of the bottom of high to medium clouds and actually increase the light level.