If you ask me, the SRFI was finalized a bit too early exactly because
of such points. [...]
I'm sorry if it was too early. We did what amounted to three "last call" periods, each time waiting until the discussion had appeared to quiesce and all issues had been addressed, only to have new issues discovered at the last minute. This time, as always, I tracked every discussion thread, trying to make sure that no feedback went unanswered. As far as I could tell, there were no open issues remaining at the point when the authors finalized this SRFI. As luck would have it, the problem under discussion here was found after that.
Still, I want to figure out how we can do better. I plan to encourage authors to extend last-call periods at least a week beyond any substantial discussion and/or any substantial revision. If substantial revisions are made, a new draft should be published and announced and the clock should be reset.
In the end, though, I will point out that last-call periods are not a formal part of the SRFI process. While they are an excellent way to determine whether discussion really is complete, and to encourage feedback by setting a deadline, they're not required, and it is up to the author to decide when to finalize or withdraw the SRFI.