Just to let you know that often we had (and still have, after 7 months of consistent no napping) periods of short nights (ca. 10.5 h). They are developmental, and whatever I do does not solve the problem. They pass after a couple of weeks. If I do consistent ebt for few days trying to let him catch up, wu becomes even earlier.
Also, for the 10-10.5 h nights with the nap: it is true that there is a point where nap steals from the night, but what I also found was that occasionally having sleeping spread between nap and night helped F to recover OT, and was actually more resting for him.
Even now, if we have a run of short nights due to some reason (sickness or late bed for holiday) forcing a nap is actually helpful to keep OT at a bay. That said, F never really pulled more than 11 h nights, we had 11.5 immediately after nap dropping, but after few months they went to 11.