I have added the 32KHz crystal on both sizes. This should save a tiny amount of power and allow for RTC operation on the larger board design. The USB BiPower board's new OTG design includes a more efficient i2c bus for communicating with the charge detection and negotiating OTG (yes, OTG is in this uc, but size and cost of a charge pump over a separate OTG negotiator is negligible). I'll be swapping some of the traces to work more efficiently with i2c and better impedance control on the USB traces.