Thanks for pointing out that link (I didn't click on it when I originally read the article). Deep in the comments, there's a hint of the reason for this port 7

Thanks for pointing out that link (I didn't click on it when I originally read the article). Deep in the comments, there's a hint of the reason for this port 7 AGU weakness: not because of the extra gates for another adder, but due to the wiring of the scheduler/bypass network, which is presumably much simpler when port 7 only handles latency-1 instructions (at least if I'm understanding that correctly). Looking forward to that paper, too!