Area 6-17+ dossier?

[Aris]

There's a bunch of mortars below a seemingly impassible ground layer. I've tried final boomerang with the split mod, but it still doesn't reach far enough.

[N'fol]

Are you sure about the number? I think I know the level you're talking about, but I'm not finding it. (What checkpoint are you starting at, then which direction to you go from there?)

I have one note for NG+ level 3_15 (checkpoint 16) that mentions mortars in the upper-right corner that you need the bow final form to reach. (And yes, I know "upper" is the opposite of "ground". )

As a general note, if you complete bonus_5, you gain the Vampire Stone, which is a passive item that slowly steals health from the closest enemy. So if you can get somewhat close, you could eventually drain it. (But there might be a much better way than that, though.) (This bonus level is right-most door on the "roof" of the main hub, unlocked after finding all the Aztec calendar pieces.)