A download manager is not just necessary, it’s critical for a browser. One of the shortcomings of the iOS version of Safari is that it doesn’t have a download manager. As a result, downloading a file involves literally waiting till the download is complete—in the meantime, you have no idea if the download has paused, connection has been timed out or if it has been altogether aborted.
Firefox for iOS implements a limited version of a download manager and it has changed the game completely by having a download manager. As a user of Brave, I would request you to do the same and introduce a full featured download manager for the iOS versions of Brave replete with a pause/resume/cancel button.