Megascan Trees impostors not working with instanced foliage

In the demo map, impostors are nice but trees are static meshes hand placed in the level.
While using the foliage painting tool to paint some trees, all imposter are broken (wrong scale, position, rotation, etc.)
I tryied to fix it but looking at impostor master material, the code is way too complex for me. Did someone was able to fix it?

Same issue here. Megascan Trees manually placed works fine however trees placed with foliage tool breaks at the last LOD