Fellow lemming hirak99 has a tool for that as well which should have better performance, but no GUI: https://github.com/hirak99/keyshift no prebuilt for Fedora unfortunately
I just typed "openrc" on the search box on the issues page. People on the internet forget nowadays that you can search, and it's quicker than waiting for an answer...
How do you know your assumptions are correct? It didn't sound that way to me. "Any idea" sounds like they have no idea, but they use the more rare init system.
I pointed in the correct direction, and it seems like they didn't search for it, as it wasn't in some super hidden place. The note was for future reference, as I won't be there to search for them in the future, and life is too short for waiting for easy answers.