The article is mostly suitably modest about mechanisms, focusing on the epidemiology of the observed effects, and it's more or less obvious to me that the transitions are disruptive to everyone, and especially so to sensitive individuals.
But there's also a bit in the answer to the fourth question (about long-term vs short-term impacts) that mentions effects of "chronic circadian misalignment". I've seen this a few times in various contexts, and it has always seemed to me that if this is what's driving some problems, one ought to be able to compare populations from different ends of an especially wide time zone, e.g. northwestern Indiana and Maine in the US, which are more than 15 degrees of longitude apart, but both in the US Eastern time zone. Surely one or the other of these groups always has at least half an hour of circadian misalignment?
Edit to add: On re-reading, I caught the bit at the end of the "abolition" question where there is a reference to what I wanted, apparently there are studies showing that people in the eastern side of the Central time zone get more sleep than people on the western side. There's even a link (to the Elsevier paywall, alas, but still...)
https://www.sciencedirect.com/science/article/abs/pii/S01676...
Edit 2: 15 degrees of longitude, not latitude.