Hi,
I suppose you can use Joomla's Pathway API to modify the breadcrumb on the fly in a view override of the product page layout.
For example, you can edit product / show_default via the menu Display>Views of HikaShop and add this at the beginning:
<?php
$app = JFactory::getApplication();
$pathway = $app->getPathway();
$names = $pathway->getPathwayNames();
$pathway->setItemName(count($names)-1, $this->element->product_alias);
?>
Based on:
www.phoca.cz/apis/1-joomla/573-pathway
Note that this code has not been tested. I've written this on the fly so it might not work, but it should be something close to this.