Hi hkelly1, currently there's no way to add custom line item properties (attributes) to the item when creating draft order.
If you are open to a workaround, you can create a checkout yourself at the store by adding the items (filled with the custom attributes value) to the cart, click "Checkout", and don't complete the checkout.
Then install the Draftable app (https://apps.shopify.com/draftable, I am the app developer). As the checkout earlier is not completed, you can find the checkout in your Store Admin > Orders > Abandoned Checkout area, select the specific checkout, then click 'More actions > Create draft order'. This will create a draft order with the product custom attributes filled.
Hope this workaround helps! I created the app because some of the stores I managed needed this function as well.