I dunno, I thought that the 'hunt' for their purpose is well & truly over. As has been pointed out earlier, the brackets are for the remote battery terminal block on the 2013 Spyders.
2013 was the year that saw the last significant changes to the frame; before then, the battery was under the seat so there was no need for those brackets & they aren't on the earlier models. But along came 2013 & the new frame with those posts/brackets, which were put there to hold the remote battery terminals, basically so you didn't have to open up the battery case that's down in the depths of the frunk. The brackets are located under the black cover under the trailing edge of the frunk lid just below the LH headlight (ie, in the top of the frunk below the headlight that's in front of the Spyder ahead of a seated rider's left knee - they're on the opposite side to where the frunk light & the 'frunk still open' micro switch is located!)
I don't know why the 1330 RT Spyders after 2013 didn't get those remote battery terminals/posts, but that is what that bracket held, and the frame hasn't had any significant changes since, and without any significant frame changes needed, every RT Spyder since 2013 still scored the brackets! Simples! :thumbup: