Adding a warning, updating the sample implementation and asking
maintainers of active Scheme implementations to check their code (this
can be a joint effort by every one of us) seems like a good idea.
Yes, I'll apply the fix to the code, add a warning to the Status section, and make an announcement on the mailing list.
Since it took over twenty years for this to be reported, and since it seems unlikely to be triggered often, anyway, I'm confident that it won't cause too much grief.
I would be grateful for help contacting any implementers who might not be on this list.