I think my favorite part is how they’ve brought back software rendering, both by allowing it on linux and by giving the option to turn off texture filtering on opengl. That plus making the main menu look like the original release brings me right back to how I first played Half-Life!
Framework is definitely not Linux only (laptops are Windows by default , but they offer a no-os option to install your own). They are however generally supportive of Linux, and it’s possible that they helped make the fingerprint reader firmware work well with Linux, though I have no specific information that this was the case.