This is interesting, I use my own FedEx account because it's got killer
grandfathered rates so I haven't seen this happen. With that said, you
can book FedEx pickups the same day, so a simple script on a platform
like Zapier could check at a set time...
We're offering a "shipping upgrade" during a post sale email campaign to
get people to go to a premium 2 day over the free slower shipping. It
would be great if we could create a rule to automatically merge an order
with that sku in it into the custo...