Seemingly the permission system seems to have a slight hickup with allowing LiteSnipers to use brushes they are not supposed to use, as mentioned in #215 by @vacante.
With that in mind and the need for Server Ops to be able to make better adjustments to who gets what, to be able to properly make the server usable and safe, it is probably easier to finally remove LiteSniper and fully integrate Brush based permissions.

Limitations on /vs range - would probably be wise to remove also (or a proper config option / permission), considering it's more of a utility: it being restricted currently twice to the brush size is rather stupid. Same thing might go along with /vc, /vh and such.

Would adding a permission for max brush size and other limitations be something worth adding? Thinking of something in the configs along these lines:

permissions:
    litelitesniper:
        max-brush-size: 5
        disallowed-blocks: [10, 11]
    litesniper:
        max-brush-size: 12
        disallowed-blocks: [10, 11]

then having permissions like:

voxelsniper.group.litelitesniper and voxelsniper.group.litesniper
Which would have those limitations.

Something along those lines, but then again: are these limitations needed? Based on MCStats; LiteSnipers were a rather unused feature.