If a channel is scene safed that means that it is “immune” to scene recalls, or that scene recalls will ignore that channel.
If a safed channel is muted and you recall a scene where it would be unmuted, it will stay muted, because it is safed. You can go into the scene safe matrix and set up very specific safe parameters so you could have everything on the channel safed, except for the mute button.
You can also do this on a per scene basis with the recall filters.
Chris