Since I was wondering: the two IFIDs in these cases both come from <ifid> tags in the iFiction XML in the Blorb (i.e., there are two such tags).
(So this isn’t the case where an iFiction IFID needs to take precedence over the calculated IFID of the embedded story file. As far as I can tell, the Babel tool does embody the principle that the iFiction takes precedence. Although in these cases, one of the iFiction IFIDs does always match that of the embedded story file, modulo this ffff-sign-extension stuff in some of the iFiction versions, which I assume is a result of an ancient bug.)