Thank you for this engaging sidebar, dear brother in Christ!
You are a blessing to me, sister. Please do not consider any of my comments to you to be more than the suggestions that they are.
So far as infants are concerned, it is clear that ALL SALVATION finds its source in the Lord. It is clear that ALL names in the Lamb’s Book of Life are clearly there and that the Lord sees them.
However, if it appears in Scripture that the Lord gives insight into WHY He has chosen to place deceased infants’ names in that book, then all we can do is weigh whether we are correctly interpreting that as insight.
In terms of “epochs,” “ages,” and “administrations,” there is also insight granted.
We must be people of the book. Any literalists should rejoice in knowing that the root word is “literate.”