Hi, I installed Openpli 8.3 in Ustym 4k pro and it appeared that there no chance to any video adjustments.
I was lucky to reveal the necessary plugin " VideoEnhancement"! It works perfect - just tested.
Unzip file and transfer plugin " VideoEnhancement" to SystemPlugins: open folder by folder till the ultimate one.
I used Total commander FTP connection.
SORRY - corrected!
Good luck!