Yes, using our Di2 adapter kit, here, the 350mm Standard Shockstop Seatpost can be used with an internal Di2 battery. The 280mm Standard Shockstop Seatpost will not work with this adapter at the moment.
The Pro Seatpost is compatible with most standard Di2 battery inserts because it is hollow at the bottom of the Seatpost. The suspension components are all housed in the upper portion of the Seatpost.