Thank you everyone for chiming in. After much trial and error, I switched to CachyOS and to my surprise everything is working out of the box just as I wanted it to: for display igpu is used and for games dgpu.
The keyboard RGB and OLED brightness controls are working fine too.
I will take this win as at a point I was thinking of installing Windows 
I’m not sure why you had issues with EOS. If it works on CachyOS then it should work on EOS. There must be something we are missing? 
Happy that you have it working anyway. I know some of these Asus laptops can be problematic to get them to behave.
Yes, if it works on chachyos then it should also work on endeavour.
Even if it would be some tweaks chachy did with the kernel, you still can install that kernel on endeavour.
But I doubt it’s the kernel as the tweaks are usually performance related, not always but usually.
But, yes if it fixed it for you and you are happy then it’s fine.
I am not exactly what CachyOS did but I noticed that it’s running 7.0 kernel while EnOS was running 6.19.
Not sure this alone would have made the difference but I think they have done some discovery and optimization for the hardware out of the box as both the live session and final installation was as smooth as it could have been