The prioritization screen is a great, consolidated way to prioritize epics or features. However, when using this to rank epics and then saving, the rank is not what is reflected in the Epic Rank field. This is still overwritten based on the position in the Features Board and is not available to sort other views. To make this prioritization more valuable and usable, the epic rank should be set based on the position in the prioritization board.
You can now send the rank from the prioritization view to a custom number field and then rerank your epics by this same custom field.