I was seeing this when testing with the Betas and at the time the issue was related to one of our security agents and its incompatibility with Big Sur. I could thankfully boot into Safe Mode which allowed me to remove the offending agent. I would start by making a list of additional agents you might be running, especially those that loaded Kernel Externsions, and verifying compatibility and/or removing to see if it allows you to boot.
We were having the same issue and initially I chalked it up to Big Sur being a 1.0 release but it turned out to be one of our security agents which used a kernel extension. So as Andrew wrote be suspicious of any of your current software that you are deploying. Check to see if they are loading a kernel extension. Exclude them as a troubleshooting technique to narrow the issue down. You can also reach out to your agent vendor to see if they have a compatibility statement for Big Sur.
I'm testing Pulse Secure this morning on a 2019 iMac PS version 9.1.8 (3999) so far it's working ok by itself under BS. I wonder is it conflicting with other security agents? I have it added under Approved Kernel Extensions. Were you using it on any particular hardware models when you got the kernel panics?
Are you using MDATP/MDE:
Extensive testing of MDE (Microsoft Defender for Endpoint) with new system extensions on macOS 11 (Big Sur) revealed an intermittent issue that impacts macOS devices with specific graphic cards models. In rare cases on impacted macOS devices calls into macOS system extensions were seen resulting in kernel panic. Microsoft is actively working with Apple engineering to clarify profile of impacted devices and to address this macOS issue. In the meantime, if you encounter such a kernel panic, please submit a feedback report to Apple through the Feedback Assistant app.