When you need to create a variation of a Civil 3D label style create a child style.
A child is simply a copy of the parent that is linked to the original style. In a child style, you can override as many of the original settings as you like, and if the original style is ever modified, those changes will propagate to the child style(s).
All the modified (overridden) settings in the children will not change.
Create and Employ Child Styles in a Profile View
Autodesk's Jeff Bartels uses Vertical Curve Profile Labels to produce an instructive how to on Civil 3D Child Label Style method and practice.From the Jeff Bartels YouTube Channel.
and the Civil Immersion blog.
Did you know you could do that with AutoCAD Grips with Civil 3D Profiles and Civil 3D Group Labels? Maybe not. You have control.
Jeff breezes over the critical Style Management issues of component naming and Label Style structure to make his important points.