Not my pics, but a very nice example. This is Funkiments loaded on an AMS spool. You can clearly see the filament bulging over the sides. This caused the guy to loose 13 hours of print time, and after the first knot he couldn't get it sorted cause he had missed a few knots.
As a side note, it is physically impossible for the winder to wind a knot into the spool. If you have knots, something like the above must have happened.
Not trying to dissuade you guys from trying, but these are the lessons we learnt along the way, hence the new spool design.
Also, to reduce the print time of the spool, use 0.28 layer height, 0.6mm layer width and crank the speed as high as your printer can handle.