You could make that a quick release/quick load if you cut the tops of the holes open, so all you had to is loosen the nuts and lift out the whole shaft and reel. Or did someone already suggest that?
Don't think it was much of mistake. I've had that same spooler for a couple of years and I still use it and ill let you know that it spools braid so tight how its suppose to be put on and I'm super impressed with how everything works.
Yes, I believe that is what he changed. The washer was causing the single nut to spin with it, but with the second nut locking in the first nut it won't move with the washer. At least that is what I got out of it.
You could have done this much easier by literally doing 50% of this build, Image it as the letter "L". Two washer, spacer and locking nut on the exterior side and interior side. Followed by a flange washer then your string, another flange washer, , a flat washer, your spring another flat washer and a Locking wingnut or a cwibg nut backed with another nut
I dont mind a shop fee if they would do a professional job. Most guys they have doing it do a crap job. I dont trust them to do my braid, esp tie my knot on the spool.