The UC AI panel is used for StudioLive Ai and Studio 192 both of which support safe modes on PC.
However it is only with the StudioLive Ai series that Safe Mode selection list will appear on Mac OS X.
When the Studio 192 is selected in UC Ai on Mac OS X, Apple's Core Audio driver does not support Safe Modes therefore the list will appear unavailable. The Safe Mode graphic place holder is still there and does not disappear.