Leveled Reader tool in Bilingual books

We are preparing to do a set of bilingual leveled books, which will have the official language variety on left side of the page spread, and a local variety on the right side. We need to apply leveling criteria to text in both varieties.

Currently (as of 5.6 beta), the leveled reader tool loads the leveling criteria for L1 only. Can the leveled text tool be made sensitive to the language of the text box in focus?

We could do the leveling in one variety, then switch L1 and L2 in the collection settings and level the second. Because of the way we are designating each text box as belonging to one language or the other, however, doing so would require copying from both languages into each text box: doable, but tedious and potentially confusing to users.