Desire/willingness to learn, and ability to learn are two separate traits.
DMT, and any other activity that allows someone to see the world through a different perspective, I believe can increases the desire to learn, as you are exposed to "unknown unknowns". Things you didn't know you didn't know, and hence creates the realization of the possibility (and potential desire) to discover/learn more due to an understanding of how much out there is to know.
Increasing ability to learn though? Rely on nootropics for that. While I believe it's possible psychedelics, while in effect, can increase a person's mental abilities to learn/imagine certain ideas and concepts more easily, I don't believe there are any lasting increases in ability once the effects wear off.
It's always kind of saddening when I meet intelligent (referring to ability to learn) people, who have no desire/willingness to learn. Knew a girl once who really didn't know anything about the world, and didn't pretend to, and didn't care. If something had no direct observable effect on her life, she didn't think it was worth knowing. However anything explained to her she would learn very quickly, and she could fix most of the electrical issues a typical car owner might experience in their car, or a general electronics issues someone might have. Those things affected her directly, and she had no problem learning how to solve the problems herself, and it wasn't difficult for her.