HI,
@bbminhtri, I am happy that is was useful for you, I enable the IGPU through clover, if you download the EFI you can see in config.plist in "devices - properties", before I had it in "Graphics - Inject Intel", with the tool power gadget I could see that it works for example when playing videos in QuickTime and also in some pages in chrome (it seems strange but I notice it in some pages), and also in Final Cut Pro.
What brand is your Vega 56 video card? I'm thinking about buying an
Asrock Vega 56 that is on sale, but I do not know if it would work in Mojave. Regards!