Yes, expanding the ‘active expand/collapse area’ for those icons greatly improves the UX. I no longer feel like I ‘missed’ the expand/collapse icon. Larger fonts in the future specific to the iOS UIs will help with this as well once that can be addressed.
A possibly related iOS Document View issue–I noticed that:
If you select a document, the Newly selected document highlights, but the previously selected document stays highlighted as the Document Viewer slides off-screen. The previously selected document should Deselect first, then the new document highlight second, then the document viewer should slide off screen. A minor quibble, I’m sure, but worth mentioning.
Tied with this: If a document (any item) in the document viewer is selected/highlighted, and you expand or collapse another item in the document viewer, both will be selected, leaving you with two documents selected at once (which shouldn’t ever be possible). The expansion/collapsing click should not highlight an item (since it does not change the currently displayed view).
Hope that made sense. Wording this stuff can be difficult.