The Teen board adds a TPS62203DBV (high-efficiency) synchronous step-down converter and a battery holder to the board and breaks out all pins in 2 rows.
The Sy board just comprises of the MINI54, switch, decoupling, power LED and a capacitor on LDOCAP (which isn’t required when using the smaller package used on the real Teensy 3.1).
I have also put up a couple of videos and photos of the Teen+Sy boards running in a previous post with the Teensy software and the Sy plugged in the Teen board can be programmed in the same was as a normal Teensy 3.1.
Teen Project Files: Are not currently being released as it was an internal test board and the pins are NOT in any sort of order.
Sy Project Files (Eagle):
Please remember these haven’t been fully tested, they are working for me but – YMMV.