NAHBS 2015: Calfee's amazing stealth SuperClean Di2 stem/steerer hides everything, plus other awesomeness! - Bikerumor
Shimano XTR Di2 1 x 11 setup | Mountain Bike Reviews Forum
Opting for a longer compression plug due to spacer height on carbon steerer. 2" and 3" apparently are only 10g apart, just default for longer one for greater adjustability? : r/bikewrench