18.04.3 was used, no kernel params needed for initial bootup and installation to succeed.
bbswitch works if the following udev rules, /lib/udev/rules.d/80-nvidia-pm.rules
are created:
# Remove NVIDIA USB xHCI Host Controller devices, if present
ACTION=="add", SUBSYSTEM=="pci", ATTR{vendor}=="0x10de", ATTR{class}=="0x0c0330", ATTR{remove}="1"