That will be me. 
I make the acrylic wind blockers for the Mk3 (all models) in clear and light grey tint. Just a little bit taller than the standard blocker.
In practice there isn’t any real need for anything taller. That height blocks the vast majority of the draft. If you really want to find out if higher makes any difference then tape a piece of cardboard to the existing blocker to find out. The only other source of draft in that area seems to be from through the hoops but that’s only a problem if the seat is well forward. Only the shortest legged drivers and passengers report this…
Here’s the link to my thread in the for sale section.