With a desktop system capable of dual GPU you choose in the firmware which one to use.
I don’t know Dell workstation - but a Lenovo counterpart e.g. my old P330 (i9-9900) will automagically disable the iGPU in favor of the external GPU.
Since you are using Nvidia using Plasma may not be the right thing as Plasma (just as Gnome) is focusing on Wayland and Nvidia/Wayland is not a fantastic combo.
I recommend trying out the reference made by @Kobold above.
There is a few treads on Nvidia - please inform yourself - not all may be applicate for you.
- NVIDIA - ArchWiki
- [How To] Handle Nvidia conflicts on sync
- The issue with Plymouth and the Black Screen
- Black Screen with Plymouth - Cause and Solution
- [HowTo] Disable or Remove Plymouth (boot splash)
If you could pursuade your workplace to switch the GPU for an Radeon 7900XTX that would make your day.
The only complete desktop system not yet embracing Wayland is Xfce - thus it may provide a much better experience than Plasma.
Rule of thumb
- Nvidia GPU work great with Windows
- AMD Radeon GPU work fantastic with Linux and Windows
Writing this from a Manjaro Plasma workstation (Lenovo P620 with Radon 7900XTX)