Hello,
This looks like a XY Problem
Why not start fixing that first? As seen in this post opened by you, your laptop has:
Apparently is almost same thing as the 5530 model. So, someone wrote more about it here
That will lead you to this github page
Then is mentioned too be an issue with the 5.12 kernel for all Precision 5540 variant laptops:
https://wiki.archlinux.org/title/Dell_XPS_15_7590#Graphics
that points to this gitlab discurrion/issue … and apparently there is a patch for it.
Not sure if Manjaro has it. @philm for sure knows.
To log in the i3wm session is enough, but to have it fully functional, you will have to do some digging and either use the manjaro-i3-settings package, that can’t reside simultaneously with manjaro-gnome-settings, then copy all the files from /etc/skel/ to your home directory, including dot files (hidden files), or create your custom config for looks-and-feel, is totally up to you, but don’t expect it to get it right from the first go without intensive reading about i3: i3 User’s Guide