As mentioned above the various replies have stimulated me into returning lists for segments and sections which, as you point out are small in number and small in size. However I'm going to provide an iterator for returning the contents of segments and sections. Parameters to the iterator generator will let me set the maximum size of blobs returned and allow specifying selected portions of the blocks to be returned. That fits nicely with common use patterns where fixed size blocks are consumed by processes such as flash programmers and debuggers. That also helps with code that might write files for consumption by flash programmers and debuggers etc.

Methods that return lists or iterators can both benefit from providing filtering so I'll roll that in as an option too. Any other kitchen sinks I should add?