It was the inspiration for my first post on the topic, but we got rapidly sidetracked in a chicken vs. egg debate over whether Androl was the type who couldn't stay long in one place because of a latent talent with a weave, or whether in this case the fact he's a great traveller, has developped spacial skills in domains like architecture and engineering, has contributed to what was perhaps a less outstanding natural affinity for Travelling that through mundane skills and knowledge he's honed to something really special.

You pointed out a quote from Maria where she thinks there's predestiny involved, but even though she has access to more material than us to make up her opinion, the fact she "thinks" indicate it's not something stated black on white in the notes (it's probably too general to appear in the notes, RJ knew the answer and either way he's applied the principle to create a great deal of channellers, he didn't need to put that to paper).

In the end it doesn't matter, it's the correlation between personality/mundane skill/knowledge and special field of affinities with the OP that's important, and between Androl and the Wisdoms who've become novices showing great skills to learn the new/real method of healing, the case is pretty strong. Those two occurences (Androl, the novices) are probably not incidental at all, it's rather a clue/sign that understanding of the OP and mundane knowledge is nearing a momenteous breakthrough, that channelers are about to understand channelling is only one aspect, and they need to develop their other skills too to really hone their OP skills, something the AOL Aes Sedai evidently understood (but didn't necessarily applied systematically... we've got two glaring exemples in Moghedien and Aran'gar, two who liked it easy and seemed to have little interest in developping their OP skills.. and who are both without known real Talents - TAR skills excluded, and for Moghedien TAR is largely a matter of avoiding direct challenges...).

If we dig enough, we'd find the evidence (notably in EOTW) that Elayne has always been interested in crafts and understanding how things work (even with more abstract concepts like politics, she's very much a person looking into causes and effects. She's probably a character who inherited RJ's "engineer" mind, thus her talent at making ter'angreal.)

And if we look at Aviendha, we see a person always keen to understand the purpose of everything, a side of her we've seen mostly in play in cultural matters. She's the Aiel always questionning why Wetlanders do this and that the way they do. There's probably a corrolation between that type of personality and her talent to understand the purpose of ter'angreal intuitively.

Interestingly, sisters with a great skill at "old style" Healing, the Heal-All-I-just-won't-let-you-die-on-me Healing are often shown as terribly stubborn, determined, single-minded and quite often they're plain bullies (from Romanda to Moiraine to Suana to Anayia, who were were told refused to budge an inch once she had taken a position. Suana described the Ajah as that of those who wished to repair what's broken, but more often than not good healers are more the type "who know how things should work, and won't give up until they work as they think it should work, and often they get what they want... Romanda is perhaps the epitome of that. People able to compromise or who change their mind too often often suck at Healing... Elayne and Egwene for instance.). People who show skills at the far more complex and really medical minded Restoring skills are different, with a real "calling" for medicine. Nyaneve is a mix of the two in her personality, and she's skilled at both forms of Healing, though she doesn't think much of "battlefield healing", which is a very unnatural concept for someone used to diagnose and find the cause, and apply the specific treatment that will have the desired effect, conscious she has to deal with possible side effects too. Nyaneve diagnoses with Delving. Healers rather used it to judge if their skill at Heal-all was great enough to work, and if the person was strong enough to survive the treament.

I'm pretty sure that without her Wisdom training, Nynaeve would never have made the discoveries she did. Her medical knowledge drove her. As primitive as her knowledge might seem to a modern physician, there was extremely little hocus pocus and superstition in Nynaeve's mundane methods as Wisdom. It's more empirical than anything, but it's still a fairly scientific approach, relying on very elaborate knowledge of active elements found in nature, and a pretty good empirical understanding of a body's working. Even if they have the skills to handle the five flows and make the weaves, a lot of Yellows would have no idea where to begin to use Nynaeve's methods as she relies massively on knowledge that feeds her intuition of how she should tweak the weaves to achieve a specific effect (and very tellingly, she seems to aim to reproduce inconsciously the effect a specific herb would have... still often by using the herb in question in parallel at this stage), and to even come close to her abilities they would need to study with Wisdoms for years to develop their medical knowledge, and that's without saying anything of women like Moiraine for whom the medical field is probably completely foreign.

There's very little doubt Elayne would develop her own skills with ter'angreal by leaps and bounds if she were to study engineering, maths and geometry, chemistry, physics with scholars at the Academies (well... her Cairhienin one anyway, her Andoran one is almost certainly gone and the scholars within lost). It would greatly refine and deepen what she does now by pure intuition and luck. Right now she doesn't understand the complex relationships between shape, matter, color and effect. She's got the mind of engineer, but she'd need real theorical knowledge to become more than a gifted amateur who can copy objects with varying success, and whose experience at that will grow slowly over the years, and reach a point where she can't advance on her own anymore without gaining the theorical knowledge she'd need.