Title? I don't need no stinkin' title.
I never said the PHB was perfect.
I’ve gone with something like your first option, by disregarding the 2-hour limit on light activity/standing watch. What this thread has shown me is that the reason I would be displeased with what amounts to your second option (i.e., following the rules) is mostly a matter of aesthetic preference.
If the purpose (or design goal?) was to have something that “works well enough”, I don’t see how leaving out the 2-hour limit on light activity altogether wouldn’t have served that purpose even better. It’s already implied for a long rest of 8 hours by the requirement of having at least 6 hours of sleep. Stating it as a hard limit only adds unnecessary (IMO) inflexibility into the system which is in tension with the flexibility implied by the words “at least”.