Bake your PLA!
So…lessons learned: When the PLA has been out of months, and the prints are failing, and it seems like the problem is extruder tension and the spool is down to the last 20%
One throws the filament in the oven at 175 F (80C) for 15 minutes. Two things happen: the filament gets really soft and pliant. If its unsupported it becomes really difficult to manage…
But then after a slight cooling, it prints AWESOMELY.
I was going to write off the spool as done, based on how long it was exposed to air and how the filament really wanted to take a tighter radius bend than the printer wanted to use.
Sure, it’s a great big messy pile on the floor next to the printer, but the end result sure it nice.