I don't know about Law & Kidd, since I think Kidd's follow up focus Arc is Lodestar (à la Bege in WCI or Law in DR).
That aside, Oda has put quite some emphasis on Urouge's pencil and also mentioned that mountain climbing as his favorite hobby.
I can't remember the whole theory, but years ago I readed about Urouge's character being associated with with the old tale of "Jack and the Beanstalk", which involves Giants and a great plant that reaches all the way up to the sky...
Plus, Urouge's Devil Fruit can really make him a giant, and usually the Worst Generation members with a central role in an arc tend to reflect the island themes in different ways.
If it's not Urouge's turn now, when?
That Pencil is clearly not a Weapon, it definitely belongs to Giants,
So i asked, why is a Pencil Important? And why Urouge out of all People has it?
What i was able to guess is that i said just like Oda's One-Shot "God's Gift For The Future", there is probably a "Book of Fate" in Elbaph which indeed turned out to be True (Harley), so i thought there should be a Special Pencil too that They write or draw with (Also taken from that One-Shot, called "Pen of Fate")
This explains why Urouge who is Theorized to be the Priest of Birka Defeated by Enel, chose to save this Pencil when his Kingdom was getting Erased, it was probably a Treasure for them (Remember that Moon People also have similar Murals) and obviously their Priest was the one in charge of Protecting it,
This made me think that there is no way Giants would give such Treasure to Humans, unless it was "Stolen",
Which explains why Sky People were Living on the Moon, and also why They were afraid to return to Earth, it was because They were Hunted by Giants & since No Mountain can protect them, then They left the Planet completely,
This would also suggest that to be able to steal this Pencil, They were living on Elbaph, and after seeing Road's Lego World, i'm convinced that Elbaph's God in the Past also had his own Community of Humans, and those Wings were Proof that They belong to him,
It also explains why Sky People were so Smart (Creating such Moon City that runs on Electricity & also Automata ... etc), because They were Chosen, Elbaph God only chose most useful Humans to serve him, but it ended up backfiring, it's because of them that there is only One Harley Book, instead of a Full Library of entire World Spoilers,
Hajrudin saving Ohara Books basically established his Future Role as a Book Guardian, and Urouge is currently Pen Guardian,
Together (Inspired by Redbeard Brothers), They must reunite & show us the True Purpose of those Prophecies/Murals & why/how They were Written/Drawn.
So you know what, not 80%, i'd say 99% Urouge should appear in Elbaph, it's definitely his Time.