Between submission and the viva you might spot some changes you want to make in your thesis.
Perhaps you see a typo that has to be amended, a sentence that could be simpler or a diagram that’s just not right. It could be you’ve thought more and now have a slightly different opinion. Maybe a paper has been published recently and that gives a different perspective to part of your work.
We can’t say that none of this matters – but it doesn’t change anything in your thesis at this stage. You can’t make corrections yet. You can’t change your opinion as it stands. You can’t write more into the pages you’ve submitted.
You can make a note for later. You can stick a Post-it Note in with a suggestion. You can read a paper and write a summary if you think it’s really relevant.
But no updates. No changes. No alterations. Whatever you call them, all the changes wait until after the viva.