Hi, so you want a dangerous life with ROG? My advice is to sort out the basic setting first, then you may add ASUS specific packages (spoiler: they are not going to do much).
To change boot options the easiest way is:
- fire up YaST-Bootloader
- go to the
Kernel ParametersTab - Edit the
Optional Kernel Command Line Parameter - hit
OKto save and regenerate GRUB.
I still think that you might be better off by installing and enabling switcherooctl according to this Switcheroo_Control.
Give it a try, you may easily revert if you find it of no use (I doubt it, see also @malcolmlewis advice above).
Then if you insist in installing ROG specific stuff you may find supergfxctlin the OSS repo and asusctlby following the steps outlined here.
As usual, ask here if you need help (and take time zones into consideration 
).