[Quoting tangent]Should I add resistors for this? It might be tricky to get them in there, but the pain might be worth it.
My sense would be that with spots for them, people can jumper. Without spots, then they have no option which could lead to issues down the road. If you don't put them in, then you might want to put the buffers on adapters so that they are easily replaceable.
Didn't someone else (Linear, National?) start producing buf634's with a different name? If so, maybe DIP-8 spots for the buffers, and custom browndog-like adapter boards for using the different buffers. This also makes it easier for someone to drop in a discrete buffer, which is bound to happen.