It seems that u-boot, the firmware and the barebones buildroot sdcard.img have been updated to 3.0.4 but there is no matching updated Debian image yet? I’ve not been able to find it anyway.
I have yet to see vulkaninfo run successfully after having tried about 5 different distros on my VF2 so hopefully the updated Debian will include working Vulkan / GLES3 support OOTB.