Yes, your comment is the only one across the two threads which understands the nuance of the definition of human subjects research. This work is not "about" human subjects, and even the word "about" is interpreted a certain way in IRB review. If they interpret the research to be about software artifacts, and not human subjects, then the work is not under IRB purview (it can still be determined to be exempt, but that determination is from the IRB and not the PI).
However, given that, my interpretation of the federal common rule is that this work would indeed fit the definition of human subjects research, as it comprises an intervention, and it is about generalizable human procedures, not the software artifact.
