The whole (short) thread didn't end because Marc had changed his mind on what is the Right Thing; it ended because it had become clear that the Right Thing would have introduced an incompatibility with the R5RS ([1]).
That's why I mentioned R7RS in my original email in this thread. R7RS is a revision of R5RS anyway so it could have changed the semantics. From the discussions that are available, it seems that it hasn't been discussed by the authors in R7RS, nor have the considerations on the SRFI 39 mailing list taken into account.
Anyway, Marc (now in CC) can probably say best how and if his mind has changed over the years. :)
In any case, even if one person changes their mind, this does not mean that the Right Thing becomes more or less the right thing (if it ever was). With this thread here, I want to acknowledge that others saw one problem SRFI 155 is concerned with before I started independently to think about these matters.
Marc
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