Good information Tom, and lots more great info. to come I’m sure, thanks!
I have been going to post something that may fit nicely here. Am just doing my spring retirement of two wire core 5/8 in. fliplines. Used to run them till they looked ratty and since I try to be vigilantly careful with my climbing gear and ropes, I often got several years of use out of them before nicking them in some way etc.. One time I started up a fir tree take down and about six feet up leaned back against my flipline, the wire core let loose and slipped right out of the rope jacket. Upon inspection the wire cable had been breaking strand by strand for some time ( judging by the old discolored breaks on some strands).
It’s a little disappointing because one flipline has zero snags or nicks on the outer jacket but, it is spring time. Installing two new fliplines this week.