Empty Category Display

Is it possible to display categories in the sidebar widget, even when the category is empty?

Additionally, if I visit the category page for a product with no listings, I get a message that says:
“Nothing Found
It seems we can’t find what you’re looking for. Perhaps searching can help.”

Can I edit this template, so I can instead display a message that says “There are no current products listed in this category, please check back soon.”

(Sorry I can’t provide a link, as the site is currently login-only. Hopefully this is a fairly routine question.)

https://wordpress.org/plugins/ecommerce-product-catalog/