Yes, of course - didn't mention it as I thought wouldn't be of much interest

In tpl_dynamic_filter.php

change

PHP Code:
case 'Checkbox':
                        $filters .= '<li class="dFilterLink">' . zen_draw_checkbox_field($group . '[]', $attributes->fields['products_options_values_name'], (isset($_GET[$group]) && in_array($attributes->fields['products_options_values_name'],$_GET[$group]) ? true : false), ($linkClass == 'disabled' ? 'disabled="disabled"' : '') . ($onClick != '' && FILTER_STYLE == 'Checkbox - Single' ? ' onclick="' . $onClick . '"' : '')) . htmlspecialchars(html_entity_decode($attributes->fields['products_options_values_name'], ENT_QUOTES)) .'&nbsp;<span class="no_of_attributes">(' . htmlspecialchars(html_entity_decode($attributes->fields['quantity'], ENT_QUOTES)). ')</span>' . '</li>'; 
to

PHP Code:
case 'Checkbox':
                        $filters .= '<li class="dFilterLink">' . zen_draw_checkbox_field($group . '[]', $attributes->fields['products_options_values_name'], (isset($_GET[$group]) && in_array($attributes->fields['products_options_values_name'],$_GET[$group]) ? true : false), ($linkClass == 'disabled' ? 'disabled="disabled"' : '') . ($onClick != '' && FILTER_STYLE == 'Checkbox - Single' ? ' onclick="' . $onClick . '"' : '')) . html_entity_decode($attributes->fields['products_options_values_name'], ENT_QUOTES) .'&nbsp;<span class="no_of_attributes">(' . html_entity_decode($attributes->fields['quantity'], ENT_QUOTES). ')</span>' . '</li>'; 
I simply removed the two htmlspecialchars references. The same edit will be needed in the 'Link' and 'Dropdown' cases.

This allows html formatting of Option Values.

HOWEVER, this also raises a previous problem I had completely forgotten about, namely that the 'special' characters in html code such as < = " > / cause filtering errors i.e. 'There are no products to list in this category.', if I remove these characters then filtering with said Option Vale works as it should.

There was a post/edit made a while back regarding escaping special characters but I was never able to get it to work for these characters.