In looking at Genesis 47:21, many translations abandon the Hebrew Masoretic text, following the LXX (and the Samaritan Pentateuch). But the Reverse Interlinear still follows the MT.
I'd like to suggest creating a way to account for the discrepancy in the rev. int. either by reconstructing the Hebrew (probably not a good idea), or by simply including the LXX. (I have no idea what language the Samaritan Pentateuch is in, so that probably wouldn't be helpful.)
Marking the rev int text in some special way would help a reader unfamiliar with the textual issues to understand what is happening.
(I understand that this can quickly become very complicated.)