Not sure if it's at all possible, but a tidal graph like this one is very easily read and even much more informative when interactive where you can slide to a specific time or date to see the forecast; Just a thought.
I have some problem to understand your explanation. Up to now, I learned that at 1500m the « average » pressure is 850hPa, and at sea level the « average » pressure is 1013hPa. But at these different levels the pressure varies.
At sea level, man uses to show the pressure measured at this level. But in altitude, the habit is to show the levels (more exactly the Geopotentiel Heights) at which a pressure is reached (e.g. 850hPa).
Am I right ?
It should be nice to have Geopotential Height layers at Windy, not only Geopotential Heights as isolines.