Shang had thought that he could use his Affinity in many different ways, and sure, there certainly were more refined techniques.
Sadly, the very refined techniques were just spells.
The ability to push the complexity of one's Affinity to the peak was literally what a spell was.
At most, Shang could slightly alter the use of his Mana.
With enough training, he could shoot out Darkness Mana.
With enough training, he could concentrate the ice and fire.
With enough training, he could absorb the light.
But that was about it. Anything more complex would be walking into the territory of spells.
Even more, Shang would probably need several months of training just to gain the control to unleash these slightly more refined uses of his Affinities. If he were to attempt to learn the most basic spells, Shang would need literal years to even learn the easiest one.
Why?
Because of his mind.