Hi,
This is handled by Joomla's HTML library for selects.
It comes from the line:
$html .= $options['option.text.toHtml'] ? htmlentities(html_entity_decode($text, ENT_COMPAT, 'UTF-8'), ENT_COMPAT, 'UTF-8') : $text;
in the file libraries/src/HTML/Helpers/Select.php
If you change it to:
it will allow for these codes to be displayed in the dropdowns. Note that this will affect all the dropdowns in Joomla.
I'm not sure if it could have consequences elsewhere.
Also, you would have to do the change again each time you update Joomla and this Select.php file is updated by Joomla.
A cleaner way to do it would be to modify the line:
$html = JHTML::_('select.'.$characteristic->characteristic_display_method.'list', $this->values, @$characteristic->characteristic_id, 'class="'.HK_FORM_SELECT_CLASS.'" size="1"' . $options, 'value', 'text', $selected, $id );
to be able to pass that option.text.toHtml option to Joomla in the file product / show_block_characteristic via the menu Display>Views.
However, I'm not sure how to change this code to allow for this.