For the Goldix 11-39 crowd: those cassettes are heavy (as noted) but the steel cog carrier is one-piece machined rather than riveted, which matters if you're a heavier rider or carry loaded bags. Riveted spider cassettes from some brands have been known to develop play between the carrier and the cogs after extended gravel use. The Goldix won't win any weight competitions but it will stay quiet longer than you'd expect for the price.

The common thread in almost every long-term success story here is that the frame was from a seller who's been around for at least a few years and has a track record of not disappearing when something goes wrong. The name on the down tube matters less than whether the factory has consistent process control. 

 The 120mm link with a 45mm stroke shock runs a slightly higher average leverage ratio, means the same air spring pressure gives you a slightly softer mid-stroke, is it right???

One detail worth mentioning: YBN links are fractionally wider than the Shimano equivalent. you might get a light tick as the link passes through. Nothing that affects function, just something to listen for before you assume your indexing is off. The Connex link hubba mentioned avoids this entirely, but they cost about 4x what a YBN costs and for waxed chain rotation that adds up fast.

Integrated aero seatposts can develop creaks from two places that people tend to overlook:
One is the wedge clamp itself. Some of these frames use a two-piece wedge system inside the seat tube, where the bolt pulls a lower wedge up against an upper wedge, expanding them outward to press against the tube wall. If those wedges are aluminum and the inside of the seat tube is raw carbon with no anti-seize, you'll get stick-slip between the metal and carbon that sounds exactly like a seatpost creak. Pull the wedge out, clean the contact surfaces, and apply a thin film of anti-seize (not carbon paste — opposite job here) between the wedge faces.

The second possibility is the carbon sleeve bonded inside the seat tube (the bore the seatpost actually slides into) has a small area of incomplete bonding. Under load, it flexes microscopically against the outer tube wall. That's harder to confirm without a borescope, but a telltale sign is that the noise changes with temperature and even worse on cold mornings when materials contract. If this is the case, it's a warranty conversation with the manufacturer.

The key to this is understanding that chainring offset and chainline move in opposite directions — an offset ring pushes the chainring toward the frame.

The 32er option is interesting . Curious to hear how it rolls once you've got it together. That wheel size seems to make the most sense for really chunky terrain...