Yes, to clear things up, our driver will not attempt to read Module-defined, Predefined, or AOI structures as a whole, at the recommendation of the Logix 5000 Controllers Data Access guide (1756-pm020).
IMPORTANT
The information described in this manual about accessing and understanding structures should not be used to access complete Module-Defined structures, Predefined structures, Add-On-Defined structures, or system tags, whether they are stand alone, an alias, or nested within another user created tag. Tags of these types have rules for dealing with host members and mapping of BOOLS, which are beyond the scope of this document. If such structures are manipulated or accessed, results can be unpredictable.
Phil has shared some of his findings about how BOOLs are mapped in AOIs and PDTs and in the future I'll probably look into this to see if there are any other risks or rule changes involved in trying to read AOIs or PDTs, but I can't really put any timeline on it.