Label for "is between" secondary filters missing

We have a situation where we have a date field and are using a secondary "is between" filter and it does not have a label for the "min" field. I'm not clear if this is totally a BEF issue, but I have found a simple way to fix it. So the BEF filter looks roughly like (warning, psuedo-array!):

array(
  '#title' => 'BEF label',
  'min' => array(
    '#title' => '',
    // ...
  ),
  'max' => array(
    '#title' => 'And',
  ),
)

So this renders the "min" text field with no label, then the "max" textfield with an "And" label. The patch attached below looks to see if there is a "min" item and adds the title if it's blank. I'm not sure if that's the best way to fix this so let me know.