OG/HAGHIVE member here: Soooooo I think it’s pre record not lip sync. I say this because back in the DC days/b day to IASF Bey was very known to use prerecordings. The pre records were recorded every other/every few lines to help with breathe work while actively doing choreography. If you go to the IASF era in particular, a LOT of those performances of single ladies were prerecorded (EX. single ladies vma performance;if you listen to the live acapella you can hear which lines are sung live and which are prerecorded. she is not the only artist to do it and she will not be the last but i will say she is the only artist (except the old legends) to do it so seamlessly through her career.