What you say about the RS not caring about AS/RO (Grantor) interactions is pretty much true. It's also unfortunately irrelevant to the point I'm trying to make about our Grantor and Resource Subject definitions up at the legal model clause level. :-)
That is, we seem to have reason to care for our purposes about correctly referring to a Person as the Grantor even if they are not the Resource Subject, and about satisfying ourselves as to whether we can successfully solve both technical and legal versions of the use cases presented in the slide deck. While the technical pattern looks suspiciously similar each time (and as you point out the RS in particular can be blissfully unaware of any changes), it's the legal pattern that changes interestingly. The ASO ends up dealing with different parties, and the AS, in fact, ends up interacting with different digital identities.
If people can take a look at the use cases and patterns with this in mind, and see if I missed anything or raise any questions, that would be great.
(And it seems it's time to switch from Requesting Party to Grantee in our definitions -- yay!)