I can't help with the Daft Spunk, but since you say you've been wanting something refreshing, I've been searching around to find a watermelon-featuring recipe that clicks for me (and my stash), and one of the comments on one I was looking at said, "
A lovely refreshing vape with really nice fruit notes coming through after the short one week steep time. It finally got my wife off custard mixes, amazing job Carole!" So I figure the mention of custard mixes was a sign, and I should point it out to you

: search for Cactus Jinx by VHB. (I haven't tried it, and haven't decided on my summer watermelon mix yet!)
(Also for a summer vape, we've been enjoying an Adirondack Placid clone lately. Search for Placid clone v7 by onmywaydownnow to see if it sounds like it might hit the spot. I like it because it's very distinctive, and not just a "strawberry with some other fruits" or "general fruit cocktail" flavor like so many fruit mixes turn out to be. Also good: Adirondack - Placid Clone Updated by psyki)