Thanks gentlemen.... some of these debates matter very little, as they are different methods of classification, a mere taxonomy.
In this case I don't mind going against the grain: in the same way it's difficult to imagine a natural language with subject-persons that differ greatly from the first, second and third persons we use (except some differences in plurals such as two, two or more, two including the speaker, two excluding the speaker), I find it is hard to imagine any noun in a sentence that does not fall neatly into the role of the subject, object, or indirect object.
That said, I can imagine nouns so deeply buried in phrases that they could hardly be considered to be even indirect objects "e.g. They were up in arms..." and so one might prefer to say "up in arms" contains no objects, but is merely an adjectival phrase of some variety.
But in the case of nouns within prepositional phrases, which are acting concretely as the victim or recipient of the actual verb, I can't agree they are "not objects at all" since they are logically implied in the action of the verb in some concrete relationship with both subject and direct object. In fact, they are merely corollaries of wordings everyone accepts as examples of indirect objects. Just wanted our learner(s) to see an alternate point of view.