Regardless, if you’re buying the cheapest computer, you’re going to get corners cut. I’ve had my share of HP shortcuts even in their elite book lines, used to buy 150-200 a year for work. They were ok, but the lower models were terrible. This em shielding thing seems weird to me, you’re saying the cables aren’t shielded on their own and interfere with computing equipment: that doesn’t have special shielding? I’ve had my laptop’s open, never seen any shielding from the outside… Just heat shielding from itself really but maybe it’s delicate and tiny?
I’ve been using a displaylink for 3 years now, mostly on Ubuntu and the past 8 months with endeavours/arch, but I don’t have the Nvidia. For me it has been the delicate art of managing updates to the kernel/evdi/displaylink packages. If one gets out of sync, I lose the use of my extra screens. If you want stable, only upgrade any of those three after checking very carefully. Typically I’ve seen displaylink support for the newer kernels lag a little behind, or an evdi update that breaks displaylink until they catch up.
If you’re more adventuresome, you can just learn how to back up to known working versions of those packages that play nicely together until they are in sync again.