Although Vaan's highest elemental affinity was fire, this was achieved through fortuitous encounters. In his present state, it also provided him with the strongest fighting power out of all his abilities.
Still, when asked which element Vaan possessed the greatest innate talent for, the answer would undoubtedly be the spatial element.
Whether it was the Heaven-Swallowing Space or Wisdom from the Void, they were his greatest advantage.
Unfortunately, he could not use any of them to their fullest potential due to his lack of spatial comprehension.
At the very least, he believed his two spatial abilities had a lot of room for improvement.
Unless Vaan could weaponize his Heaven-Swallowing Space or perceive hidden information in the space with Wisdom from the Void, it couldn't be said that he had been using any of the two to their fullest potential.
