Very interesting. And there is no memory for the life of the line?
My small Pfleuger President reel has given me nothing but problems. I tried multiple types of fishing line, I spooled the line then stretched it, used line conditioner and I would still end up cutting off 20 feet of tangled mess every time. I finally got sick of it and haven't touched conventional gear in 6 months. My next reel will be a Snoopy spin cast, LOL!!!!
If you mean monofilament, the analogy I'd use is cooked versus uncooked spaghetti. The cooked noodle is softer and more pliable, but at a cost: loss of tensile strength before a break.
All studies I have ever seen show that monofilaments degrade rather quickly in sunlight. This is because of oxidation. Not so for fluorocarbon because it has much tighter chemical bonds. Back to mono: it loses about 20% of its strength in a matter of a few hundred hours of sun exposure. It also loses about 20% of its strength when it is saturated with water.
I am not sure what happens when mono lines are saturated, then dry out, but my guess is it is serially weakened over time.
But, the good thing is mono is usually cheap and it simply has to be replaced more often than braid or fluorocarbon. Fluorocarbon has to be re-tied frequently owing to its more glass-like properties but up on the main line length itself, unless it is scraped really badly, it suffers little degradation by temperature, sunlight or water.
I think soaking might be okay to make a mono supple, by the way, just at some costs in other areas.