You only need to transpose one pair of letters in one sentence on one page in your thesis and you have a
miskate mistake. A reference could be wrong or a diagram might need redrawing. Its likely you’ll have typos somewhere in your thesis. You could have words around switched switched around or paragraphs that need another edit.
You don’t do any of these on purpose, you want your thesis to be the best it can be. So do your examiners. Corrections aren’t a punishment or “just another part of the process”. Corrections are your examiners helping you find things to make your thesis even better. Perfect is a nice ideal, but better is the real goal.
Mistakes are almost unavoidable in the tens of thousands of words you’ll put in your thesis. Aiming for perfect won’t work. Aim for great, and after the viva you’ll get some help aiming for