I've seen this used in various ways for various reasons and I think we can give the concept a name. If you have a particular addition to your walls that only occurs in some places, add a componant into your wall style and give it a 0 width. Say you have a corbel only appearing on the front of the house, or a feature niche in the entry, or a rendered feature portion on a face brick house. If you add a body modifier, you need to apply it to a componant in your wall style. If that componant has a 0 width, it won't appear until you 'awaken it' by adding the BodMod or applying a profile. Using this technique, rather than a special wall having to be isolated from the other styles, you can just add a 'sleeper' componant to the main style and 'awaken' it where & as required. Of course you may now have to adjust settings for that additional componant in several DispReps and also set your componant priority wisely.
You can now also control the material of this componant via the wall style rather than via a ME style or some other separate object.
WARNING: Be aware that adding a componant may mess with your endcaps. I don't often need them but if you do, push the sleeper to the end of the list & you should be ok.