Inline popup with multi and/or select2

almostcompletely

I have an advanced module that I call from a simple module's record edit page. It pops up a form which I use form_builder to create (I have a button with the class="btn_field add_inline_button")

$fields['newReferences']['label'] = 'Add these references';
$fields['newReferences']['type'] = 'multi';
$fields['newReferences']['options'] = $options;

$this->form_builder->set_fields($fields);

It seems that the "multi" field type does not get initialised to show the "supercomboselect" implementation of the field. I get a similar problem with select2 - it doesn't initialise.

Should I expect form_builder to initialise the fields?
Should I expect it to work within a popup?
Should I be adding js to the field to get it to initialise, if so what (for multi & select2)?

Thanks.

almostcompletely

Seems I had a rogue

$this->form_builder->auto_execute_js = false;

Also need to include

$this->form_builder->load_custom_fields(APPPATH.'config/custom_fields.php');