Checking In products is one of the super-powers of Manage Comics, it allows you to quickly get products allocated to specific customers, and get rich listings up on your Shopify website immediately.
If you get items in "mid cycle" without a full invoice, you can still check them in and create products quickly on the Shopify side.
Pulls are great, but orders are how you get paid...fast!
How to organize and view your pull list information