Yeah, there’s a few seatposts being recommended here that do nothing for compliance, and nor do they claim to.
The split Ergon/Canyon post works really well. Only available in shorter road bike lengths last I looked, but doesn’t need as much post showing as others to do the job. I’ve also seen a identical ebay knockoff work just as well and not explode. £30-40 if you can find one.
Syntace, Cannondale, Niner and Ritchey do carbon posts designed to flex slightly. They’re all fairly pricey new. I’ve had the Syntace before and it does indeed visibly bend slightly when leaning on the saddle and is noticeable while riding.