Since R7RS-large is a large language, it's also appropriate to add
something like this. (I would not have advocated keyword args for
R7RS-small, and I think it's good that -small was kept simple. It's
interesting that even case-lambda is in its own library in -small.)

Would you prefer to have `let-keywords` or some similar construct in
R7RS-large instead? (I mean to ask in a neutral tone; not intending to
start an argument. I have confidence that this group will eventually
make a good decision one way or another, so I don't feel threatened by
exploring alternatives.)