We teach that the Atonement and God's grace that underlies it have the power to save all, regardless of their individual "disabilities". We also teach that all will, at some point in their eternal existence, have the opportunity to be judged on their own individual merit. When we construct speculations that are extrapolated to many from what was given to a few, we necessarily exclude others who struggle with disabilities that are just as real and difficult for them. In effect, like the Oliver Cowdery example of feeling a burning in the bosom or a stupor of thought, we end up setting conditions and expectations that might or might not apply to each individual - and we risk incredible harm in doing so.
Personally, I know of WAY too many investigators who felt the Spirit, believed we had the truth and had a desire to join the Church but waited because they were told by the missionaries that they could feel "an overwhelming burning in their bosom" - and who took the absence of such a burning as a stupor, thus never joining the Church. In very real terms, they were placed into a "disabled" category that never should have been applied - that was flawed in its very composition, since, like me, they simply don't receive answers in that way. I believe they paid a heavy price for being held to an incorrect standard.
Where does it stop? Why do we exclude some and not others? What makes someone with DS or MS or a form or mental retardation or schizophrenia different than someone who is bi-polar or suffers from chronic depression or is deaf, mute and/or dumb (or blind) or any number of other inherited manifestations of the effects of the Fall? What about someone who is raised in extreme bigotry and succumbs to that bigotry through no conscious choice of their own? How do we define what is an individual exercise of agency and what is not - thus defining what is covered by the Atonement and what is not? More importantly, why do we need to make that determination? Why can't we simply accept that Jesus will make that decision for us and treat everyone the same way within the limitations of their own disabilities?
All of us are disabled in one way or another. Why do we need to label some and not others when it comes to spiritual things, separating them from us in a very real way, when all of us are in the same boat from God's perspective? Why do we need to imply that all in one category are better or worse than others in different categories? I simply prefer to say, in all cases, "I don't know; I won't judge."