Looking at how the Vision Quest is going, I wonder if there's anything we can do to help future shamans succeed at the challenge.
Generally, for Primordials, the answer for a problem is 'make a demon to do it', and that may be the case here. Either temporary demonic spirit guides or permanent merger with a demon might help.
Less scalable, the Destiny Background might help, and we can probably grant it. More exclusive options are things like True Faith, which we know most people can't get,
And, while it feels like it shouldn't, as the Vision Quest seems to be a combination of mental and social challenges, giving people the Mega-Mental and Meta-Social mutations, peak human Awareness, Socialise; and Presence, and the related Ability Aptitude merits might work.
There are some Mage merits that may apply but may be too niche, like Astral Vigor, which makes you safer when astral projecting, which I assume a Vision Quest is. Depending on quite what the nature of the entities usually encountered by non-Primarchs on a vision quest are, something like Celestial Affinity which gives you a strong intuition of how to interact with conceptual entities might also help.
A merit like the Code of Honour, which gives bonuses to Willpower roles to uphold your personal code, might also help in dealing with trails of character. Lorgar can probably design a very appropriate code for our people, and I can see him being able to effectively grant people who he teaches directly the merit.
There's also the every important Common Sense merit, which I think Fan should grant to every child in the tribe as a matter of principal and kindness the the parents, but on a more serious note could be very valuable in case a child develops psyker abilities.
If we do create, demons as spirit guides, giving them something like the full version of the Drahma's Voice merit:
Whether you're a child, a drunk or a monk, you speak with more wisdom than you possess. Perhaps you are a reincarnated sage, or you simply have an intuitive connection with the Absolute that expresses itself in your voice and actions.
In game terms, your character is a Mentor for Akashic mages (and, at the Storyteller's discretion, others who might understand her words,) despite the fact that she isn't particularly wise herself. The four-point version of this merit turns your character into a one-dot Mentor - you may add more dots at a cost of one point per dot. For six points, your character serves as a three-dot Mentor to other people, even if she lacks the usual knowledge to teach in such fashion. She can't benefit from this herself. She doesn't know why the other Sidai light up with sudden understanding when she tells them a joke or a bar story!
It might also be worth granting this merit to some of the tribe's elders right now.