As a QA tester on Audacity I took a bleeding edge approach an upgraded to Big Sur on day 1 - see my report in this Sticky thread:
https://forum.audacityteam.org/t/audacity-on-big-sur/59307/1
Basically all 64-bit versions of Audacity 2.3.1 through 2.4.2 work fine on Big Sur - and so does the latest alpha test version I have for the upcoming 3.0.0
WC