The data for the graphs com from WU and there is only UV data available, no solar.
As it is still not clear if and how WU will continue access to out own data, I will start after my vacation with new graphs based on the new WU-api.
The 7 day data contains both UV and solar. There can probably be a meaningful UV-solar graph added.
I do not understand what what you mean with ET-index.
There is a calculated ET-value (Evapotranspiration) when there is a Davis console but not all weather-programs deliver that.
There are requests for soil-moist sensors and extra temp-hum sensors, so the ET-value can be added to the list of new weather-values.
Be aware that the WU-data does not deliver any ET-values as I am aware of.
Use for all these and further “wishes” the special “wishes”-topic => http://discourse.weather-watch.com.new#new
There we discuss the needed enhancements to the template for the next version.
Wim