I find the left one better, but still very cluttered.

Many categories could be merged to keep it more glanceable and create less choice paralysis.

The list to the left is the way to go, but maybe we should have subcategories or some other type of grouping within them?

I don’t know UX design, but I know I feel they both are a bit much to take in and not intuitive to navigate.

I like the Gnome settings app better! 😄

Fun read! I’d like to do something similar if I had any control over my apartments heating at all… Sadly it is all just manual valves on the radiators.