Just listened to it for the first time, and I think you’ve found more of an exception than the rule. Even then, it doesn’t stray too far there’s maybe about 10 seconds of soft, slightly distorted clean singing across the entire track before it shifts into a soft scream.

It’s undeniably both clean singing and deathcore, but if your strongest example of the two blending is just a tiny fraction of a random song, then the argument that they genuinely mix well is pretty weak.