I got a solution for the input lag problem playing on PS4.
Input lag ist distracting and annoying and i hope it get fixed/tweaked with a new firmware.
Until then i set the output resolution on the PS4 to 1080i.
The VAVA doesn´t upsacale to 4k and displays a smooth 1080p(i?) resolution.
I know,it´s not perfect but it works and still looks great an a big screen.
Maybe VAVA team could implement a “output 1080p” option for gaming only?