The Point Of Prep
Remember that your viva prep isn’t the point. Being ready for your viva is the point.
You need to plan your prep but the plan isn’t the point. It mostly doesn’t matter what you use to annotate your thesis, except that it makes your thesis better for you and your viva. You’ll probably benefit from a mock viva but the conversation with your supervisor isn’t the point.
Being ready is the point. How you exactly get there is less important than getting there.
Figure out what you need to get you to “ready”.