Today, if you want to place an order for a client using the admin panel ("Add New Order" page), There is no option to add addons on the order you place.
To do so, you must place an order first, then go to the product page and add there an addon.
If you need more than one addon, you will need to repeat the process and enter each time to a different page and create different addon.
If the ability to add an addon will be added to the "Add New Order" page, that will be more efficient for us, reduce the time it takes to create those orders and everything will be on the same invoice without the need to create separate invoice for each addon and then merge all together.
The client should receive one order confirmation email with all the services he has ordered.
I think that it will make the order page more usable and it can be added like we are changing configurable options of product from this page, adding domain, and adding more than one product.
I have created an image showing where I think it could be added, please look at the attached image.