Add a step for artwork proofing and approvals to the hub.
How I envision this working:
Orders go into a proofing queue like the digitizing queue (optional). In my workflow I download the order artwork files from deco, do any manipulation needed to get them ready for production, also make a rendering of how the item will appear (since this is laser engraving), and export that as a png. Then I send them the png for their approval or to ask for changes or approval.
With deco, we could upload the png to their order (order attachments could be part of this) and have it email the customer about a proof being ready. Have a place for comments, and buttons to Approve or Request Changes. If approved it moves into the production queue. Otherwise it stays in proofing queue and notifies us of changes requested.
If there is no response to the email after X days it should automatically send another message.
Bonus: If the customer requests too many proofs it could warn them that an additional charge is required to receive more proofs.