AAA, NAC, Guest Access & BYOD

Question- Should we avoid sending authentication traffic to the publisher to reduce load on the server?

Answer- Yes, generally a separate dedicated publisher node would be recommended. Even though the Publisher would be capable of processing huge amounts of authentications, a burst of traffic being unpredictable during the peak hour in addition to any other background network authentication/replication, etc (that the publisher is expected to perform), could cause a significant load on the publisher.
As a side note, you can also enable insight on the Publisher and the standby publisher to be able to generate reports, etc."