Number of open shopping carts limited to one?

Summary: Is it possible to have more than one shopping cart in self service procurement or does the order need to be submitted before a new order can be started?

Content (required): Users that submit orders on behalf of others may have a need for more than one order to be in process at a time before submitting to workflow. Is it possible to have more than one shopping cart opened at a time?

Version (include the version you are using, if applicable): 22C