Okay, it turns out that the “Experimental” Feature Set option was a red herring. It doesn’t actually matter whether the “Supported” or “Experimental” Feature Set is used. It turns out that opening Edit > Preferences is what actually gets GPU rendering to work.
Corrected summary of how I got Blender Cycles to use my Radeon RX 5700 XT on Fedora:
- Followed the instructions which were written by u/szooloo & repeated by @bhibb
- Followed @joni999’s extra steps
- For every new Blender session, before rendering with Cycles, opened Blender’s Preferences menu.
The Preferences menu does not need to remain open for this to work.