HD-2 and HD-3 and beyond are counted as originator if they have a translator as the translator is dependent on the HD channel for its license.
If an HD is repeating an AM or another FM (as signal fill if the HD signal is on a better FM than the one being rebroadcast), then the originating station gets the credit. The source, not the dependent, is listed. That means the HD, even if most of the audience is on the auxiliary service.
If the stream for a HD subchannel is 100% simulcast (meaning no ad insertion) and is encoded, it will be counted as HD listening if the station requests total line reporting.