Zero 3W gadget mode random MAC address

I am always getting a random hardware address when using the Zero 3W as a usb gadget. On Raspberry pi I edit the /boot/cmdline.txt file and add:
g_ether.dev_addr=12:34:56:78:9a:bc g_ether.host_addr=16:23:45:78:9a:bc
I can see that the Zero 3W uses cdc_ether instead of g_ether… is there a similar boot command that I can use?
Thanks.