Certain kinds of feedback can be useful as you prepare for your viva. By that stage you can’t make any changes to your thesis. Feedback has to be carefully targeted to things you can change.
If you have a mock viva it will help to get feedback afterwards. Focus on the good stuff. Ask questions that you want thoughts on, rather than simply see what your supervisor says.
If you rehearse by sharing your research or having a conversation with friends then ask key questions. Were you clear? What did they not understand? Was anything confusing?
When discussing your thesis with your supervisor after submission, remember that feedback has to drive action. Critical comments or things to think about must have real purpose behind them. If a method could be challenged then how could you respond? If X is open to interpretation then what can you do?
Time is limited after submission, so feedback needs to be limited too. To get good feedback ask questions that you really need responses to – and consider before you ask how you might act on them.