Overall correct analysis.

Re 11pm coffees my thoughts:

There are different ranges of body clocks considered acceptable in different cultures. If you get some sleep in nap form you can stay up later. Ive been around people who eat dinner at 9 or 10pm as a normal thing too. Whereas others consider 6 as late.

Don’t forget about coffee additives like chickory which decrease caffeine. And there are some methods of coffee that are deliberately weak, like having very coarse grinds. I read about it once I can’t recall all the details. But it was done on purpose for this very reason.

Factors affecting all this are how externally regulated your time is, like if your whole social groups economy is based around a need to be at work 5am every single day then all night coffees won’t be popular for working adults. If early mornings are absent, seasonal, optional, can be missed now and again or made up later then you can indulge. I wonder how proximity to the equator where days and nights have consistent durations effects this one way or the other.