lowradiation,
I totally agree with you, but Sales people will try to sell anything they can whether or not it is a great idea; regardless of what we think.
I totally forgot that the default keymap does come up that way for the 6900 series phones, but we have already diverted from that. I do believe that if you put a + sign behind the extension number that you can dial extra digits instead of making it a BLF Extension key. Without looking at a system I can't remember how we did it, but I know it works fine.
Thanks,
TE