There’s lots of advice about how to prepare for the viva. I’m personally responsible for sharing a lot. But none of it is beyond question. For a long time in workshops I shared a few approaches to making paper-based summaries, then realised that not everyone might like to write things longhand. That was simply my preference.
There are core areas to focus on for viva prep, but there is no right way to work on any of these areas. Your goal ahead of the viva, like any other PhD candidate, is to feel prepared. You have to figure out your own path to get there.
Listen to others, but don’t follow blindly.