Hello, super happy with M4 sofar. Easy install from SD to MMC, it is fast with Friendlyarm Desktop 18.04 dec 19, 2018 release. but HDMI output defaults to 1920x1080@60. Works fine for most scenario's but i want feed some big 4K screens on the wall with NanoPI. Tested with LG 27UD68P en IiyamaPL2792U...