I tested out VIM3L_Ubuntu-gnome-focal_Linux-4.9_arm64_EMMC_V0.9-20200530 … nice work!
However, Hotspot function does not work.
After a bit of digging it appears that the problem is because hostapd has no config.
Specifically, the solution is to create /etc/hostapd/hostapd.conf with contents:
interface=wlan0
Hope this helps someone.