@codepoint, you will probably have to flash that .ffu to an SD card and flip the "SD BOOT" switch on the back of the DB410c.
That will probably work. Microsoft's instructions unless you've deviated from them, create FFUs that are intended to be flashed to an SD card. If you're not adding the
/skipplatformcheck parameter to the end of the
dism command, add that when flashing to an SD card.
Please report back with results on 1080p! I want to know if this is possible.