Very good question. I'm intrigued. May I further your post and ask if they're on the Bongo 4 as well? How about for the 5 string guys between Bongo 5 and SR5?
Are the S.U.B. Stingray's rear routed? I seem to recall someone, maybe BP, maybe not, saying that all 'Rays were rear routed now and the silver plate was there for looks. In the spirit of disclosure, I must admit that I am planning something evil for the S.U.B. I just bought.