One POV is hard to do. I agree that you can switch POV at a scene or chapter break. The number of POVs you need depends on the complexity of the stories.
I believe we shouldn't switch POV anymore than absolutely necessary. But that necessity will be different with every story.
Do remember that each POV character also needs a clear arc. Hop into the block for discussions if you feel like it. ;-)
Thanks! My original novel mss had 3 POV characters. An editor hated it, I think in retrospect because there was a section where the same sequence of events were retold from three different perspectives. I've since removed that device, but I think at least 2 POV characters are needed to tell the story. I'll stop by the Block if I get a chance this weekend!