I would revise this request with further modifiers.
Regular Click/No Modifier = Relative Limited (Once one event runs out of fade range, all events no longer fade futher)
Click+Alt = Relative Compressed (All Events will continue to fade in/out irregardless of each individuals limits)
Click+Alt+Shift = Absolute
Note: Because some of these modifiers are used for other things, it would have to be programmed so that either these modifiers apply to fades only when the mouse is hovering over the fade triangle, or, after a fade has already been click-grab initiated.
FolderEvent Slip Editing
Modified Click - Select All Events within FolderEvent Range
Relative Compressed and Absolute fade-drag modifiers