Currently "products on sale" page only shows products for which the 'list price' was filled, but it ignored discounts applied via 'promotions' module.
Is there any way to list both types of discounted products on a single page?
Thanks!
Possible, but fairly complex to implement since you'd have to run the promotions sub-system for each product in a listing and then evaluate list price versus price. Note that this would only pick up catalog promotions and not cart promotions for the products.
I do not know of any existing addons that provide this functionality. Assuming you've searched the marketplace.
Possibly the following module can help you
https://marketplace.cs-cart.com/add-ons/marketing/cs-cart-discounted-products-page-add-on.html