How does elves' trance affect time spent for XGE's long rest crafting rules?

Question

XGE gave us the option of having tool proficiencies (e.g., alchemist's supplies) enable a character to craft an item "as part of a long rest." For races that need 8 hours for a long rest but only 6 hours' actual sleep, that new way to use tool proficiencies made some sense. A character could be productive with his or her time spent at "light activity," i.e., resting but not specifically sleeping.

Since the August 2017 Sage Advice update, elves get all the benefits of a long rest in 4 hours, rather than 6 hours, if they trance during the rest.

How does an elf craft an item, per XGE, as part of his or her long rest?

I'm perfectly willing to hand-wave this at the table, but I'm curious as to whether anyone can come up with actual reasoning better than the unsatisfying reasoning I've come up with myself. (I'll keep mum on my thinking for now, lest I influence the discussion.)

Answer 1

They craft twice as fast

The rules don't work any different, so since their rests are half as long they can accomplish twice as much in the same amount of time.

Answer 2

There is no difference for crafting Alchemical supplies for an Elf vs other creature

The language in Xanathar's (page 79), which are optional rules, only specifies that it takes up part of a long rest. There is no specific language with regard to number of hours, so this is merely a result of completing a Long Rest and a successful DC check.

But what about watch?

Because it doesn't cover exact time, it leaves it open as to whether or not you can craft Alchemical supplies AND participate in other activities such as a standard watch. It will be up to the DM to determine if crafting can be done in conjunction with watch duty.

Answer 3

By the rules (and optional rules from Xanathar's) as written, there would be no difference in how crafting such an item "as part of a long rest" would work for an elf vs. any other race.

However, if you do implement those rules, you could also houserule that the item crafting would have to be done during the (up to) 2 hours of light activity allowed as part of a typical long rest. If you did so, it would be logical that an elf that tranced for its long rest would need to spend an extra (up to) 2 hours outside of their trance to craft the item; assuming they have non-elf party members, they'll have 4 hours outside their trance when their party members are sleeping anyway.