During a long rest if someone is fully rested, can they keep watch longer than 2 hours?

Question

So I am currently running a game with 3 PCs, 2 of which are Elves and 1 a Human. I am just trying to calculate the most efficient way to run watch shifts during long rests since both of the elves only need 4 hour meditation to be considered fully rested.

In the PHB pg 168 in the section about long rests it states that (emphasis mine):

A long rest is a period of extended downtime, at least 8 hours long, during which a character sleeps or performs light activity: reading, talking, eating, or standing watch for no more than 2 hours.

Now my question is, once a character is considered fully rested and no longer needs the "long rest" are they able to keep effective watch for longer than a period of 2 hours? So say that the elves both finish their 4 hours, can they now keep a vigilant watch for the other 4 hours the human PC needs to rest?

Answer 1

Yes

If your character is not resting, they can do whatever they wish with their time. But if they did not rest themselves, they would not get the benefit of a Long Rest. However with Elves, they only need the 4 hours for trance, and since you have 2, it would effectively get you through the night.

Trance (PHB, 23) is defined as:

Elves don’t need to sleep. Instead, they meditate deeply, remaining semiconscious, for 4 hours a day. (The Common word for such meditation is “trance.”) While meditating, you can dream after a fashion; such dreams are actually mental exercises that have become reflexive through years of practice. After resting in this way, you gain the same benefit that a human does from 8 hours of sleep.

Given that the full benefit of long rest is granted after 4 hours, they would be able to stand watch the remaining time of the long rest for the other PC's.

However...

You will need to stagger how it's done, because during the 4 hour trance, they can't be standing watch. So having one Elf stand watch for 4 hours while the other rests, then switch, while the human gets to rest for the full 8 would be a successful 8 hours with someone on watch at all times. The Human could also use 2 of the 8 to stand watch.

The 2 hour limitation is only there for characters within the Long Rest framework, not a stagnant game rule.