Why write out all the flats all the time at the start of the stave? i.e. you're writing for some crazy reason in Cb Major and you have to put 7 flats at the start of the piece. They'll always always be in the same place (right?) - why not just shorten it to (7b's) or omit it entirely and just say the key THANKS
usually a key signature will actually never be more than 6. if you are writing in Cb i would suggest do it in B instead (5 sharps). other than that i'm not sure. i think it is nice to have it there to indicate what notes you really mean, just in case aliens read it or something