Turning an old flagship phone into a handheld
A three-year-old flagship with a clip-on controller is a surprisingly capable handheld once you strip it down. I removed the SIM, turned off almost every notification and uninstalled everything that was not an emulator or a file manager.
Performance is not the issue; thermals are. Long sessions on heavier systems throttle the chip after twenty minutes or so. A frame cap and a slightly lower internal resolution fixed most of it.
Updated GPU drivers made a real difference for a couple of demanding emulators. It is worth checking for them every few months.
Would I recommend it? If the phone is sitting in a drawer anyway, absolutely. It costs nothing and gives old hardware a second life.