Thank you sooooooo much. I spent all day fighting with this. For anyone else I added these 3 to the tunables in the webui, rebooted, then ran the upgrade without it crashing.
vm.pmap.pcid_enabled=0
hw.ibrs_disable: 0
vm.pmap.pti: 1
vm.pmap.pcid_enabled=0
hw.ibrs_disable: 0
vm.pmap.pti: 1
"