Being able to select items or collections that I don’t want to be apart of the sale would be helpful. When doing a sale on my website I find myself wanting to omit less items from a sale rather than items I want to be apart of the sale. Every time I want to do a site sale I have to make whole new collection with 200+ items, making me manually select 100+ items because Wix only allows the first 100 newest items to be selected all at once. This is very time consuming. The reasoning behind wanting more freedom when selecting what items are apart/omitted from the sale is so that items that are already discounted wont be double discounted allowing customers to have the opportunity to get items on sale discounted even more (sale on sale).
Another option would be allowing to apply the discount code to more collections rather than just one.