... probably most of the things you can suggest to us. It is just that in our philosophy many of the platforms build for elementary schools are in our eyes either:
The general selection criteria for our soft- and hardware choices is described here. Below is a list of platforms we worked with but decided not to focus on for now.
Raspberry Pi (RPi): The hardware where our adventure (re-)started. We have many various versions of them around the house and use them as Linux computers for many purpose. Additional hardware for the power-supply, the memory card and other details, made it less suitable for our physical computing ambitions. Also the current cost of the original RPi made it less suitable for our needs However we are exploring the Orange-Pi-zero which seemed to have solved some of these issues.
The BBC Micro:bit please add