Personally I wouldn’t change a thing if it’s working fine now so shortly before a gig. No matter having a time machine backup and what have you. You won’t be restoring a backup in the middle of a gig!
Unless you are experiencing/have experienced the problems the update says it solves, leave things as they are, including the iTunes library, although this should be a sliglty easier thing to do. Copy your entire iTunes directory to the external drive, set the external drive iTunes library as the active one (not sure which key to hold when starting iTunes on the Mac, but I am sure Google is your friend here), fire up Traktor and see if all works as advertised (forgot if you have to point Traktor to the iTunes folder too in settings). If it does, you can remove your original iTunes folder. If it doesn’t, return the local iTunes collection as your standard and nothing has changed, no harm done.
Hope that helps some
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