All Addtional Attributes for Grouped Products in Magento

Question

Similar to the question asked at: http://stackoverflow.com/questions/1005394/magento-show-custom-attributes-in-grouped-product-table

I'd like to display attributes of simple products in the grouped product page.

However, I need it to work such that you do not explicitly specify which attributes get displayed. Instead, it displays all the attributes that would get displayed on the simple product view of that product.

I've tried variations of:

(from /template/catalog/product/view/type/grouped.phtml)

<?php foreach ($_associatedProducts as $_item): ?>
  <tr>
            <td><?php echo $this->htmlEscape($_item->getName()) ?></td>

   <!-- important problem part -->
   <?php foreach ($_item->getAttributes() as $arr): ?>
    <td><?php echo $arr->getData() ?></td>
   <?php endforeach; ?>
   <!-- end of problem part -->

            <td class="a-right">
                <?php echo $this->getPriceHtml($_item, true) ?>
            </td>
            <?php if ($_product->isSaleable()): ?>
            <td class="a-center">
            <?php if ($_item->isSaleable()) : ?>
    <a href="<?php echo $_item->getUrlPath() ?>">View</a>
            <?php else: ?>
                <p class="availability"><span class="out-of-stock"><?php echo $this->__('Out of stock.') ?></span></p>
            <?php endif; ?>
            </td>
            <?php endif; ?>
        </tr>
    <?php endforeach; ?>

And other variations, however, I cannot limit the attributes being displayed to just the ones I need (i.e. just the additional attributes displayed on the simple product view; those set as Viewable on Frontend). Any ideas? Thanks in advance.