ief referenced entity with a multi-value field is getting broken somewhere.

I have an ief widget on a node edit form, through which I create a new entity which in turn has a field with 'unlimited values'.

If I create the entity in the IEF form and add 2 values to the field, then save and open the entity form a couple of times, the entity form won't show all the values for the field, just the first.

I notice this function - EntityInlineEntityFormController->cleanupFieldFormState does some clearing out of $field_state['items_count'], presumably for a very good reason. But then later in field_multiple_value_form it looks to this value as it loops around and adds widgets.

Does this seem like expected (if unfortunate for me) behavior? Or more likely it is a symptom of a problem somewhere else?