- Edited
Perhaps a good compromise to allow keeping the current ability to run multiple profiles at the same time (which is extremely valuable) would be to use the current action when selecting the profile in the menu bar, but set it up to allow option-clicking to replace the current profile (by "replace" I mean launch the new one then quit the old one). This would somewhat be in the same spirit as the macOS functionality of option-clicking a window of another app hiding the current app while switching, as well as the well-worn practice of offering alternate functionality throughout menu bars when option is held. Visual feedback could be provided by replacing the the small "{N} windows" text underneath the profile's name with e.g. "Swap Profiles" when option is held.