Where do the Limenial exalted fit in? Just curious as they pop up almost offhandedly in the book but they dont really seem to have a part in most of the lore.
That would be because they don't really have any part in the lore. Liminals are random experiments/ attempts to resurrect the dead gone wrong. Or to create some other kind of "almost-life". They're a relatively new idea, both in the real world and the in-fiction world, they show up in Third Edition and right at the end of Second Ed. I'm not personally that fond of them. But not much is known about them either.
Not much has changed really, mostly just tidying up some of the more problematic stuff by older writers, and adding new locations like the Dreaming Sea. I did at one point consider making a 'lore differences between versions' type of video, but I've since moved on from Exalted content on my channel. So you'll either have to ask elsewhere or do the research yourself and make your own video / post to infrom others. Goodluck!