So, how did it go? Well, it did not work. But thankfully, it was due to an initialization bug of OpenChrome DRM. I was able to read kern.log located at /var/log/ and that appears to be the case. In other words, the issue is fixable. The version of OpenChrome DRM I tried is Version 3.0.57. This is the current bleeding edge of drm-next-4.13 branch.
I wanted to get a confirmation that this USB flash storage device is going to work with OpenChrome DRM, so I sticked into another computer with ECS VX900-I mainboard. Fortunately, it worked like a regular computer with a hard drive / SSD. I tested standby resume, and unfortunately, the display (VGA) got disrupted. It appears to be a fixable bug.
From my own testing, I got OpenChrome DRM to work on VX800 chipset based mainboard called VIA EPIA-M830. I will assume that OpenChrome DRM was not really tested on VX855 chipset by the previous developer, and I will need to go fix the bug down the road.