The flyline coating problem are "long term"..unfortunately you don't know until the next
winter of steelhead fishing after summer(june) fishing in alaska in june..which sucks.I don't know what you would call it as far as 'eat' or just 'corrode' or "crack'..the lines don't really disinegrate as much as crack across the line everywhere..every couple feet you get a break down to the dacron center which seems to hold up.it just sucks when you are trying to throw nice loops and the line hinges flat and fails at the broken points.I had to replace all my lines(I used there) every year after going up there at $50-60 each...I was using 2-3 Teeny brand lines..extra pricey ones..
I'd soak one of your items(a little more than normal use,considering multiple exposure to the deet) and check it in winter to see what it does to it...It may break a lot of strands where they fall apart..or maybe nothing.
Up there I used deet springly but the bugs eat you so bad by the swarms it's hard to not use it,especially while walking river banks in the tundra and stirring them up by the hoards...vicious b@st@rds!

If the clouds are so thick you can't see the top of the mountain from the bottom..what the heck makes you think it'll improve the other direction!Realityguy