Increasing aetherial capacity

[Contiguouskittycat]

We've seen several characters improve or augment their own aether. Some by normal means, like Arya who in training as a Red Mage strengthens her aether to become an accomplished mage, even after losing her voidsent blood given magical gifts.

We've also seen this happen by underhanded means such as the resonant procedure and various eugenics experiments in several plotlines.

My question is: Is strengthing one's aether the same as increasing aetherial capacity, and are there any training and/or procedures to improve this to provide accessibility to people born with an aetherial disadvantage?