It's probably not "bad", but at the limit of the spec makes it fair game for replacement.
Personally, I go for the pull away from the rear sprocket test over the 21 pin/ 319mm, (or whatever it is), as I find that a difficult measurement to do accurately, but if you are confident in your measurement it's better to replace than have a problem.
I recommend denniskirk.com for a matched set, either RK or DID. Fair prices, good customer support.
I don't want a pickle, I just want to ride my motorsickle. A. Guthrie.