Breath is a unique form of investiture in that is, at least some what, intertwined with the spiritual realm. Each person born on Nalthis has their own small well of investiture. Endowment can also use Breath to bring a soul back from "The Beyond" with a Divine Breath. Because of the nature of this form of investiture people can choose to relinquish their well, and either give it to another, or invest it into an object. However, when they do this they undergo a very clear transformation. The most notable changes is the how their skin, hair, and even the clothing they wear seem to lose color, and they become undetectable to people with Perfect Life Sense (The 4th Heightening). Drabs also seem to be more susceptible to some illnesses.
So it made me wonder, in a world where EVERYONE has some investiture, and losing it makes you less, does relinquishing ones stock cut them off from entering The Cognitive Realm? Do we know of any Drab world hoppers?