Now that I have another Centigraphe (the cmmnsens edition) I was able to run the one test I hadn’t run on my previously owned piece-the power reserve when the chronograph was continuously running.
Journe advertises 20 hours of autonomy for this feature. I ran the chronograph continuously to see what I’d get.
The watch ran for 33 hours and 22 minutes before coming to a complete stop. After a short time it ran an additional 10 minutes.
As for accuracy and consistency of rate: the watch was perfect for 33 hours. (Within a second.) The last 20 minutes could be characterized as “jumpy” and the balance visibly speeded up.
I haven’t even had a Lange as accurate as my two Centigraphes. Bravo, François.

Don’t worry: I tested the watch well before pouring the Beefeaters.