The upcoming release of GNOME 50 to be found in the likes of Ubuntu 26.04 LTS and Fedora Workstation 44 will feature improved discrete GPU detection within the GNOME Shell. This effort has been two years coming and finally merged this week.
This merge request to improve dGPU detection within the GNOME Shell was opened back in February 2024 and finally merged yesterday to the latest Git code for GNOME Shell 50.
This works now in GNOME by using switcheroo control. You right click the tile and choose discrete or integrated launch, it remembers that till you change it.