I think this is a feature that should be reintroduced. As plugins continue to be written and the ways to evolve the data into visualization - 3D is standing in your way from turning really good into great. I cannot think of another WMS browser that decided to punt 3D due to lack of demand. If it was decided on a statistical preview of the site, then I would consider possibly relocating or changing the UI to accommodate it. There are a few things actually if you're gonna go that far... Maybe increase the amount of screen by closing/fading/hiding the right bar and left bar more compact - it's huge! That's a lot of screen real estate even on a tablet which that 3D feature could once again shine... (wink wink)

I would like to be able to specify more parameters for alert notifications. Specifically things like cloud cover, wave direction and height, etc..

The FAA has all their printed aeronautical maps online at: https://www.faa.gov/air_traffic/flight_info/aeronav/Digital_Products/

Doing a quick perusal of the offerings, it seemingly can be done but would require a WMS server to store the data. That said, as an example, I found http://wms.chartbundle.com/charts/tms.html does have a WMS online and seemingly could be introduced as another overlay.

And NOAA has Maritime maps online at their WMS: http://tileservice.charts.noaa.gov/tileset.html#50000_1-locator
https://nauticalcharts.noaa.gov/charts/noaa-enc.html is another offering.

I think the biggest problem - especially globally is actually to hunt/find and either host or reference a related GIS server for those countries/governmental authorities. Not impossible, however. A community cache of these GIS servers would also be beneficial when the GIS servers are down for maintenance or just simply decommissioned without notice or arrangement.