Regarding preferences among options 1--4 posted in an earlier message, I
would prefer option 2, then 3, then 1, and (by a big margin) 4 last.

Option 3 certainly adds many names and bulk but I don't think the
conceptual load is very high given the common pattern.

On a related note, I think SRFI-43 has continuing value despite the
existence of foof-loop (which is certainly very useful when the added
features are desired).  One compelling reason for me is that I find SRFI
43 can be digested much more quickly than foof-loop (by someone familiar
with RnRS definitions and conventions in general), but that may well be
something specific to me.

Regards,

-chaw