We are also desperately looking for a solution. It has been over 2 years of complaints on this issue and no progress?
Some suggested using Shopify Plus plan, but our business is still on the smaller end and going from $400/month to $2300/month just to have customers hold an item for a few minutes in a cart is HIGHLY unfeasible. One person making 5+ orders a day to not miss out on an item creates a mountain of manual work with printing, organizing, picking and marking ready for invoices. What can be done about this???