I am using Kopia UI on Mac.
Well… KopiaUI doesn’t support config sets, but you can connect to multiple repos at the same time. KopiaUI stores its configs under
~/Library/Application Support/kopia/repository[-<id>].config
if you want to save those, feel free to do so, but I don’t know, if messing with these config files manually is a good idea.
Well, not the answer to the question itself, but yes… that’s where you can connect to multiple repos. However, when you disconnect from them, e.g. when starting KopiaUI and one ore more repos are unavailable, you need to remember to leave those alone, until the repos are available again. It’s rather easy to accidentially disconnect from them or remove them otherwise.