@nprofile1q... why do you think DDR controllers do link training? That's a noisy RF link with reflections! Of course you need to treat it like that to squeeze out the last bit of performance to get a 3600 MHz clock rate going over stupid FR4 in a bunch of narrowly routed microstrip lines (not even "proper" transmission lines!).
I honestly think you're way deep in denial here how ubiquitous "parameters that nobody but a very narrow group of experts can understand" are.
You might be one of the experts,