It reads more like they did the logical thing.
ML-KEM is the new NIST standard for transferring a key (ML=Modular Lattice, KEM=Key Encapsulation Method). It's the default choice for a post quantum KEM.
With the ratchet, the logical thing to do is to tack on a third cog using ML-KEM. That's what they did.
Also you need to accommodate the huge numbers that ML-KEM uses. That's what they did.
It's a fine design, done well and deserving of praise - especially deploying a hybrid scheme against the best efforts of the NSA to stop that, but I don't think it counts as an amazing engineering achievement.
Calling is SPQR is pretty funny for someone who grew up in a formally Roman fortress town.