After the yielding leader has time to get back on the end of the line you may gradually adjust your speed. Glass, trash, road kill, potholes, and other impediments. All things we do NOT want to run over. In a pace line, only the lead rider has a clear view of these things as the line approaches them, and it is his responsibility to notify everyone else of their presence. This is easiest done for obstructions that can be seen from a distance away.
Traffic is also a consideration.
You may need to gesture to distinguish your guiding move from a pull-off move. If you are not going around an obstruction, someone in a long line is almost certain to hit it. When you are the recipient of one of these notifications, pass it back. Those in the back of long pace lines often do not get the word, which is one reason we have so many flats while riding the bike lanes. Roger Pierce is a member the Gainesville, Florida, Cycling Club.