There are two types of possibilities to apply specifications:
No limitations. You can create as much as you need.
Yes. You can give a discount on specific products. When you will create a new specification then it will ask you to choose any one option
Unfortunately, we have not added features to add limitations because as many discount codes will be sent to the customer. Customers will purchase many products from your stores.
No. Shopify doesn’t allow its customers to use more than one discount code on the checkout.