Another thing to consider is although you are flying paid J, theres a reasonable chance that the concierge might just direct you back to the priority lineup if you aren't SE. I've never tried to use a concierge without being super elite, but there have been plenty of times that they've asked me if I am super elite when I walk into their office.

So for the novelty factor I wouldn't try it, since it might be the opposite of novelty.