Because I'm a glutton for punishment, I decided to test a bunch of PCDuino3 images. Hopefully this will be helpful for someone. Feel free to double-check my work.
3.X kernels work perfect.
4.11-4.14 no HDMI Audio
4.19-5.8 there's a bug where the console won't show up if you connect a high resolution screen. It complains about not enough memory reserved for the frame buffer. So if you have a blank screen, it's possibly working, but you just can't see anything. Also, still no HDMI audio even though it's built into the kernel.
5.9-current hangs at "Starting Kernel" showing in the serial port.