In the last beta, you create also more simple buttons for the weather, which was still good. What I'm really missing, was that I can have a short look during flight how the rain was moving. Only solution was to chancel planning and then to have a look. Most of us have min 3G in flight, so the possibility for an update was available. Ok there will be argument again an solution, but better to switch between different program.

If what we've had recently isn't heavy rainfall, I dread to think what is!!
Joking aside, the Poland screenshot is helpful ..... it's a bit like when we had to get used to the earth not being green on the BBC weather forecast, it looked wrong for a while, but eventually you get used to it, and it's better.
Back to the question on transparency - I wouldn't make it any more transparent than it is - small clusters of light rain are already quite subtle.