If you've been to a career fair in the last 12 months, there's not really a tangible benefit to attending another, UNLESS there were significant your application or you didn't do so well the previous time, but an applicant will have no indication of his performance.
If you've just sat in the seat for six months and have 6 x hourly average and there has been nothing specifically new, meh, I wouldn't bother.
There are no "points" or "score" that an applicant needs to ever concern himself with at any time. Forget the word "tier" ever existed because it was roundly misinterpreted and, at the end of the day, the criteria is fluid.
There is no consideration given for the number of times you've spoken with a recruiter at the various job fairs.
If you have spoken to them in the last 12 months and haven't made much progress, take the weekend off. There is no bells or alarms that are going to go off and there is no brimstone that will rain down.
If you have spoken to the team in the last 12 months and there IS tangible progress, it may benefit you.
If you don't match the minimums stated on the registration page, there is zero benefit. All of the sweet talk in the world and shined shoes will not make up for no degree or lacking 1000 hours of turbine (no PIC requirement). Literally the buck stops there.
Sorry, studying for CQ in another window and felt it needed more clarity.