There should be other ways to obtain the Field notes.

[LaylaTsarra]

It's not just one rare drop it's many of them. I have one left to get on my main Layla which is note 45. My Balmung alt Alys is at needing 43/44/45. My Siren alt Talea is at 17/43/44/45. It would be nice if one could trade a 5 star for a 5 star but I suspect what will come at some point is an increase in the drop rate. When that will happen is anyone's guess.

The same ones seem to be the issue with 12/14/17/43/44/45 being the main culprits. At least with Dal note drops the mettle awarded helps with the Proofs of Mettle but that sure can't be said for Southern Front. I suspect I'm going to be running somewhere in the 50 run area before i get the drop if I'm lucky. She is currently at 15 and I'm planning on 2 or 3 runs a day if I can manage it.