Last year I used to be very active on your excellent Windy.com site. Back then weather radar wasn't showing for New Zealand. Just noticed it now is. I did nudge MetService to try to be a little bit more cooperative for you.
Looks like they are but there's still room for improvement. It seems Metservice are providing you with hourly data. Weather places for other places (e.g. Australia) show much more dynamic weather radar.
Just had a look at the MetService weather radar:
Noticed it shows at increments more frequent than hourly. So they are collecting the data. Any reason why MetService can't provide Windy with more frequent updates?