It looks like if you take the M_Puddle_Master, and change it from [Material->DecalBlendMode->Stain] to [Material->DecalBlendMode->DBuffer Transluscent Normal Roughness] it works as I would expect. This is in the material Parameters, (select the master node that everything is connected to and look in the details panel for those attributes)
Note: the emissive component doesn’t come through then, unless you go to the color setting, but then all of them are milky again… so until this is fixed it’s an either or situation.