Update; Turned out I was wrong about Redcrest not being an elder despite his grandfather status. In one of the last published chapters, Wavecatcher refers to him as "old Redcrest" - so he must have been born way earlier than the + 700 years before WD#1 I originally had him at, during the first 9000 years of the Disappearance.
Since Coral's boat is said to be his "first", that means he discovered his plantshaping gifts when he was already elderly, so we have an late bloomer compared to Wavelet (who I believe was a pretty average age for an elf-child when her powers manifested) and exceptionally early bloomers like Leetah, Mender and Korafay.
Which leads me to wonder what he might have been like before becoming the tribe's resident plantshaper. Hey, remember the talk about his hair going to and fro between straight and short and long and curly? Maybe he was the WaveDancers hairstylist, after all! If the Gliders had two elves working over Clearbrook's 'do - nothing forbids Redcrest is their WD equivalent, no?
Who knows if there were other plantshapers in the tribe before him and Wavelet? Probably yes, considering the great number of magic users... but if he had been the only one to shape wood, it might explain why no WaveDancer ever tried to leave Crest Point in over 9000 years (although admittedly, it was a safe enough home for most of the time! Humans only showed up in more recent years, after Redcrest had come into his own.) I know it's not-canon, but didn't the slave girl Windkin rescued from that troll say something about her tribe's migration/s and how it involved swimming, not sailing? If they had to swim all the way to Crest Point (and she made it sound like it wasn't "a flick of a fin"!), obviously they would not endure the same hardships without a good reason.
But once the tribe had a wood-shaper to shape trees into crafts that could carry them across the ocean, and humans began a nuisance - little wonder the youngest tribe-members leaped at the chance to sail off with Zephyr!
(BTW speaking of Zephyr, Embala pointed out in the thread about Shadowcrest that of the two elves pushing Coral's lifeless body into the water, one looks like Haze - but the other definitely looks like a younger Zephyr! Given he's about as tall as Haze (who's a grown-up, and with adult daughters to boot) that would make Zephyr a few years older than Wavecatcher & co, logically when you think he was the leader of the expedition. My bet is that he was at least 120/150 years - already taking responsibilities upon his shoulders, already mature for his age, already confident and enough self-assured to lead a band of young WaveDancers into unknown waters, some 200 years later.)
Will update the timeline later on but it's good food for thoughts and takes me one step closer to place the births, deaths and facts in the right order!