As an intern project years ago I had to all the BLS data into a database for analysis. Any time I ran into an issue I would call them directly. Little known fact that every BLS data set has a source.txt file with a phone number to call. You might think of government agencies as massive bureaucracy, but I was amazed at how helpful and knowledgeable everyone I spoke to was (and that the calls were answered at all). They would answer my immediate question and often explained the logic that went into the data structure.
Making survey data structured is quite challenging and I gained a lot of respect for the work they do.
Anyway, if you go down this rabbit hole, maybe make it an IRL rabbit hole and giving them a call may help get to your answers quickly.