Thanks for your question.
At the moment, SKYBOX supports Dolby TrueHD, DTS-HD and Dolby Atmos. But Dolby Vision and HDR 10 bit videos may not be perfectly supported in SKYBOX. We are working on optimizing the player. Please be patient with us 🙂
And you can watch 4k videos without any problem. In fact, SKYBOX supports up to 8K video playback. The streaming quality depends on your Wi-Fi and the hardware of your device.
Hope that helps. Feel free to contact us if you need further help.