LocalizationFeature should be concrete type?

[cserteGT3]

Current implementation:

abstract type LocalizationFeature{R,M} end

struct HoleLocalizationFeature{R<:AbstractHoleGeometry,M<:AbstractHoleGeometry} <: LocalizationFeature{R,M}
    descriptor::FeatureDescriptor
    rough::R
    machined::M
end

struct PlaneLocalizationFeature{R<:AbstractPlaneGeometry,M<:AbstractPlaneGeometry} <: LocalizationFeature{R,M}
    descriptor::FeatureDescriptor
    rough::R
    machined::M
end

Can I replace it with something like:

struct LocalizationFeature{R,M}
    descriptor::FeatureDescriptor
    rough::R
    machined::M
end

const HoleLocalizationFeature = LocalizationFeature{R,M} where {R<:AbstractHoleGeometry,M<:AbstractHoleGeometry}
const PlaneLocalizationFeature =  LocalizationFeature{R,M} where {R<:AbstractPlaneGeometry,M<:AbstractPlaneGeometry}

R and M must be handled separately, because it is possible, that those are of different types (a mesh hole type and a primitive hole type for example).
Does it change if #3 will be merged?