I've just tested my pcDuino3 and pcDuino3nano boards. I compiled Ubuntu 18.04, Dev kernel as headless and desktop for nano and non-nano) with vagrant.
Interestingly, the nano "flavour" seems to work fine on both boards (4.20.7-sunxi Kernel , HDMI, USB, Nework on pcDunino nano (except for the not-working network on the pcDuino3 board, obviously).
But I cannot boot the non-nano version on either board. I connected a serial output and it hangs at:
U-Boot 2018.11-armbian (Feb 07 2019 - 13:21:03 +0000) Allwinner Technology
CPU: Allwinner A20 (SUN7I)