Boolean facets have no labels

OK... so I did some digging and found the _search_api_facetapi_facet_create_label() function, which seems to handle Boolean facet values as a last resort. Unfortunately, my values never make it that far, as they are caught in a earlier section of code meant to handle option lists. Following the rabbit trail, we eventually end up in the entity_metadata_field_options_list() function in the callbacks.inc file of the Entity API module, where a module_invoke() is called with NULL $field and $instance variables eventual returning an array with two empty strings to the _search_api_facetapi_facet_create_label() function, which is then used as labels for my Boolean values.

I am changing this to a bug report as it appears it has already been implemented but is not working correctly! Please let me know if I can provide any other information.

I discovered today that this is only happening when the display widget is set to 'Links with checkboxes'! When the widget is set to 'Links', the true/false values show up.

*Edit: Not sure how the above was ever possible, but I cannot reproduce it.

OK... I could be wrong, but this seems to be a core issue with the Options List sub-module not returning default allowed values, but instead is returning empty strings. Per the 'On value' help text 'If left empty, "1" will be used.' and the 'Off value' help text 'If left empty, "0" will be used.', I would expect the list_allowed_values() function to return the following:

array(
  0 => '1',
  1 => '0',
)

but instead, it returns the following:

array(
  0 => '',
  1 => '',
)