From what I understand, the roadmap for new features is usually not announced until it has been implemented. This is probably due to changing priorities, and the difficulty of a particular task might mean it gets delayed longer than originally expected.
Since the feature hasn’t been released yet … and it looks like it will be a large piece of work for the developer to complete … don’t get your hopes up about it being announced soon.
I recommend you try to find workarounds in the meantime. Maybe there is a manual way that you can keep track of your orders, until this is implemented? (e.g. spreadsheet)