Most(all) of these attributes are from acs_objects, and not all acs_objects are cr_items/revisions.
If I were to use these fields, I would use them just as they are for every other acs_object (when they are used). And that means that if you modify the object, change the modification info. Not all modifications are revisions, in fact, I would think that in general, attribute changes are not revisions, and shouldn't be tracked as revisions. Otherwise you run into a whole series of logical problems. Minor typos or fixing obvious non-factual mistakes, are not revisions either, but they could be handled (and probably are more easily handled) as a revision. If not, do an in-place edit and change the modification info.
But each item/revision is a distinct acs_object, not to be confused with the versioned object in the cr.
