Thanks for your additions. I think that some basic synoptic features are useful for a wide group of windy customers. Maps with very special parameters for people with a deep understanding of meteorology and thermodynamics would be a waste of (development) time.
In my opinion, the possibility to combine maps from different pressure levels allows to evaluate the weather situation on a synoptic scale and is a good balance between costs and benefits.
The following example combines precipitation with 500hPa geopotential (made with Photoshop) and shows what I mean. Now we can see the cause of the predicted surface weather in the upper air: