I use this feature to toggle reverb decay from a low time to a long time or to toggle the reverb mix amount. This also works well for amp settings on a single amp. If you assign two settings to the same switch say gain and channel volume. This allows a quick change from low gain / high gain.
Can you have more than one switch affect the same parameter? In your example applying boost to the mix level on the delay; could you have two switches boost at different levels or would they compete too much with each other?