I have five prototypes assembled and tested, and I'm going to take them next week to Europython to Edinburgh and pass them on for testing. We decided to skip this year and I'm for next year, which will give us more time to develop the libraries and examples for them.
In the mean time, as I'm working on the #PewPew Standalone, I'm getting ideas about how to reduce the parts count and price of those badges. Since I'm using two 7×11 matrices, I can drive them with just 18 pins by using a kind of charlieplexing approach — that means that a bigger SAMD21 chip should be able drive them all, and still have spare pins for breaking out. That could shave off as much as ¼ of the cost. Of course the cost of that would be scanning the matrix in software, but I already have to write the library for this for the PewPew.
I also still need to get the radio going. There are ready NRF24 libraries, but I think we will want to have something custom more similar to Micro:bit's "radio" library.