I believe every single child, who dies before they have an understanding of right and wrong, are and were elect from before the foundation of the Earth, and purchased by the blood of Christ.
Children are born sinners and sinful. Fully deserving of wrath, yet not having this sin credited to their account, until such time as they have the mental capacity to sin with a full understanding that it is wrong. The sin is not credited to their account, until they sin, "With knowledge."
Rom 7:9 I was once alive apart from the law, but when the commandment came, sin came alive and I died.
Rom 7:10 The very commandment that promised life proved to be death to me.
Rom 7:11 For sin, seizing an opportunity through the commandment, deceived me and through it killed me.
ALSO:
Rom 5:12 Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned--
Rom 5:13 for sin indeed was in the world before the law was given, but sin is not counted where there is no law.
We see a couple of things in these verses: #1, There is a time when someone does not have the law. #2 They are "alive." #3 When knowledge of the law comes, they "die" thus fulfilling what is said in Romans 5:12.
I think this understanding is crucial, rather than the more "popular" understanding of the "age of accountability." God does NOT save children because they are "innocent." Children are every bit as sinful and wretched as anyone else, and deserving of the wrath of God. Yet, they are preserved through the mercy of God, until such time as they willfully sin. This is not an age, but a level of understanding.
According to your position, it would be better to leave the unreached peoples of the earth in spiritual darkness, unaware of the law & person of God. If condemnation comes with knowledge, instead of natural spiritual state, then are we not condemning them through our evangelistic efforts? Leave them in ignorance and they will all be saved. To me, this position goes too far in justification through ignorance.