Can I calculate foliage radius or LOD phase in the Material Editor?

I’ve been using the following graph to calculate my static mesh’s screen size so I can create my own, improved transitions between LODs:

This works perfectly for static meshes and is much much cheaper and less noticeable than dithered transitions, however, for some reason this method doesn’t work with instanced foliage static meshes and I’ve determined it is due to the Object Radius node which does not seem to work with foliage.

I’m wondering if I need to calculate the radius differently for foliage, and if so, how?

If not, is there a way to recreate how the engine is calculating the LOD transition distance within the Material Editor? I really find the dithered stippling quite expensive and noticeable on foliage.

Thanks!