Just an observation...
We use braid for bottom fishing......it's going through ceramic eyes on the rods and the line is constantly being hauled up and down on a typical jigging trip.
It doesn't take too long before the braid starts showing signs of wear.
It starts to get "furry" on the outside of the line.....and the braid itself seems to lose some of it's "woven" characteristics.
At a certain point.....after continued use...I can take 80lb braid and break it with my bare hands.
I only get one season out of a roll of braid for jigging.
So maybe it might be prudent to change up downrigger braid on a regular basis "just because".......and not wait until it fails inexplicably.......