I second that. This is a great feature and should be added.
Here is why:
We sell books on our website. Books can come in different formats/packages. For example: printed book, ebook, a package of both the printed book and ebook, used book, etc.
Historically we had different products in HikaShop for each variant. That was cumbersome to manage, and decided to switch to using a single HikaShop product with multiple variants. This makes management simple, and puts the end user buying experience more in line with how other online book sellers do it.
However, we have issues when it comes to coupons, as the coupon applies to the whole product and not a specific variant. Also, we can't manually create an order for someone in the backend and add a product with a specific variant. These are two major issues with the management of products going this way.
So on one hand having separate products for each variant works in those cases, but makes our management more time consuming and the end user experience not as nice. Or we can use a single product with variants and simplify our management and the end user experience, but make coupons difficult, as well as adding manual orders.
I think this is an area of HikaShop that needs some serious attention. We would be willing to pay to get this addressed in a more timely manner.