Does this process work for let’s say DRM encrypted music too?
No. These use Widevine DRM.
As you can tell from the security section of the article, it is not exactly impossible to crack, and I'm certain private groups have their own way to get past it.
But if you're just looking for audio, then you can just record your computer's output audio stream.
Steam Deck is based on Arch Linux & folks are trying to get as close as possible on their other PCs I assume.
PS For future reference, does this sort of exposed PCB trace (pad?) used for electrical connection take solder well?
I can't tell if you have gold plate or just raw copper (probably gold. But in either case, yes, it is solderable. You can think a little bit about how they manufacture the boards. First the print on the green solder resist, then they dunk it into an electroplating bath for a gold finish, or a dunk it in solder for HASL. It would be a lot of trouble to go through (=$$$) to individually mask off that part of the board for some special process.
Open it up!
They put a regular old switch inside a fancy box, but you'll be able to read the part number once you see the actual switch.
Unless you've managed to get a switch made out of superconducting material and you're working inside a liquid helium bath, everything has resistance :)
You'll have a bad time trying to measure such low resistances, so usually you can look at the datasheet for the switch you're using or for a similar switch if you need a ballpark number. You'll see an on-resistance, and a max current (since there will be arcing when you open the switch).
If you do want to measure the low resistance, you'll need dedicated meter with a kelvin connection.
I've seen different numbers in the same font on many circuit boards. What does it typically mean?
1