The thing with the above is that it shows a fraction of the amount of stations we do, simply because it would get too cluttered otherwise.
I think that the most common use of METAR on a map is to determine the conditions along your planned route, so showing the flight category should be enough in the majority of cases. If you need more details, you can always grab the full METAR and TAF reports in both raw and decoded formats by pressing any of the icons on the map!
This answers the quoted question, but feel free to explain your use case!
Do you think that the legend could be improved? It currently shows which colors correspond with rain and snow, albeit with quite bad contrast because of the changing colors:
I am probably not understanding your question fully. Apologies if that is the case! The weather radar images come from a source that we cannot change, so we cannot change the colors either if that is what you are asking!