I have been continuing my reading on the Hundred Days campaign.
Biggreenbugeyedmonster leant me his copy of The Battle of Quatre Bras 1815 by Mike Robinson. I have also been reading "A Military History and Atlas of the Napoleonic Wars" by Esposito and Elting of West Point
It is clear that the Imperial Guard Lancers are performing all the tasks required to be defined as Pursuit.
On the 15th of June the Guard Lancers are screening ahead of Ney's force heading towards Brussels. They make first contact with the Allies at Frasnes and manoeuvre them out of that town.
On the 16th they initiate the probe towards Quatre Bras in the early afternoon, attempting to fix the location of the Allied defenders ahead of the lead infantry attacks.
On the evening of the 18th they are one of the units screening the flight of the French from Waterloo.
I'm less clear on what the Chasseurs de Cheval of the Guard were doing, beyond being brigaded with the Lancers fighting in the Quatre Bras campaign, and whether they also justify Pursuit in the same campaign
I guess that this is all well known and as part of the editing process to keep the French lists manageable it was decided to have just one Guards Cavalry list. Had more space been available it would have been plausible to have a Heavy and Light Guards Cavalry List. The Heavy would be as current (consisting of the Horse Grenadiers of the Guard and the Empress Dragoons). The Light would gain Pursuit and probably lose Shock to compensate. They would consist of the Guard Lancers and the Guard Horse Chasseurs.
It would of course help with using the Imperial Guard when they have a single support choice.
cheers
Russell