I also use my laptop daily so I needed to get both of my HDMI output and USB-C to Displayport working. I needed to update a few boot parameters. Also, I noticed that my WIFI wasn't full speed. I have a DW 1830 and needed to add a flag for increasing speeds.
The only apparent problem I have at the moment is my HDMI out is limited to 3840x2160 @30hz. I'd like this to be @60hz but not sure how to get it there yet. I'm not 100% sure if the Whatever flags are needed for 4k but it helped me and I needed my machine up and running as soon as possible with both screens.
I thought this may help others.
Markdown (GitHub flavored):
# Added to boot-args
`-cdfon -igfxmpc -igfxhdmidivs brcmfx-country=#a`
# Whatevergreen flags
-cdfon (and enable-hdmi20 property) to enable HDMI 2.0 patches
-igfxmpc boot argument (enable-max-pixel-clock-override and max-pixel-clock-frequency properties) to increase max pixel clock (as an alternative to patching CoreDisplay.framework).
-igfxhdmidivs boot argument (and enable-hdmi-dividers-fix property) to fix the infinite loop on establishing Intel HDMI connections with a higher pixel clock rate on SKL, KBL and CFL platforms.
# Enables 867Mbps speeds