No. For 4K Netflix the browser needs to talk to a specific, locked down, part of your Intel (!) CPU. This only works on Edge in Windows or Safari on MacOS (it also works with the Store apps). It never works on Linux and it does not work on Chrome or Firefox.
Could that be achieved with “Chrome on Windows” spoofing on FF?
No. For 4K Netflix the browser needs to talk to a specific, locked down, part of your Intel (!) CPU. This only works on Edge in Windows or Safari on MacOS (it also works with the Store apps). It never works on Linux and it does not work on Chrome or Firefox.