Subject says it all..
I can see metafield values on the ordergroup in "Meta data" section
Do we really need to override the view?
I'm not sure exactly which meta fields you're referring to and what you're trying to accomplish. Can you specify an example screen in Commerce Manager?
For example i add a metafield called DeliveryDate (type: datetime). When i create the shipment i specify this date shipment["DeliveryDate"] = myDate.
This field (and value) is rendered nowhere in the commerce manager as i see it, and i guess we need to override the PurchaseOrder-ObjectView if we want to render it.
I am actually considering not to override the view, but make a complete new one. I also need other customizations, and i really to think its easier to create stuff for my self than trying to override/change the existing codebase.
Oh and here is a screenshot from the view i where i want the information to be shown
It seems likely that you have to modify the PurchaseOrder-ObjectView.xml in order to render new meta fields because there is no way to modify the meta fields on that page you showed via Commerce Manager alone.