Hi everyone,
Thank you for joining the conversation here. I appreciate all your feedback on this topic. While this is still not something that can be done without any customizations to your store, I wanted to let everyone know that your feedback is being shared with our developers for consideration.
@whitewater you specifically mentioned “We don’t want discount codes being used to purchase marked down sales items.” While we don’t directly support the ability to apply a discount code to a compare at price, you have full control over what products a discount code can apply to. I do recommend making collections of products for specific discount codes to better organize and control where discounts can be applied.