I’ve messed about with the jack socket as much as I can stand. It’s been fine for a couple of days after being cleaned out; it’s gone crackly again.
Ordered a Neutrik replacement.
Also, the action was great, but I felt it was a little high at the bridge end, so without much travel on the saddles left, I added a small neck end shim just to give me the option.
Holy crapola - this thing plays amazingly well...