Hello,
No need to give you access.
This can be reproduced in a clean basic Joomla installation with the latest versions of:
ja-megafilter-component_2.0.2
ja-megafilter-content-plugin_1.1.7
It can actually be seen as a problem on Joomla 3 as well.
See screenshots below:
Where the {render_class} is entered in the field
Where the {render_class} is entered in the default file:
plugins/jamegafilter/content/layouts/default/product-item.php
The result in the frontend (No {render_class} is displayed where it should be)
It worked correctly on previous versions, but it must have be broken in some newer version.
Note: It's not just {render_class}, also {label_render_class} also doesn't work