As with all the other Flex Modules, I will be improving the castellation design shortly. In addition, I may try to add more GPIO pins. As the shield and the 3dB Molex antenna are similar heights, I can get away with closer trace routes with that antenna. So in addition to it being probably the highest gain chip antenna (especially for the price), it also improves the design. I'll also likely move to a 4 layer stack up, so I need to recalculate the co-planar waveguide. We should be able to start selling these when ready in the next month or two as a Flex Module is a "subassembly" not requiring certification. We will try to get it certified when it becomes popular.