Alright, since I haven’t heard back, I gave it another spin and made it happen 
I literally recreated material setup from Showdown because I couldn’t wrap my head around the noodles. Then it turned out that ground plane is always fixed. So in order for shadow to show up, I had to tweak it manually and it didn’t really work when there was different floor elevations. So I added BP to adjust that parameter every frame. That worked wonderfully.
Another observation I made was about these fake shadows not acting as decals. So it’s they would be used on a terrain, the edges of the shadow mesh would wedge into terrain and will be clipped. Looks pretty ugly.
Here is what I am talking about:
Full image: http://s30.postimg.org/lg1hoiv2n/blob_shadow_clipping.png
How can I make attached (via sockets) static blob shadow meshes to be always parallel to the floor ? (so no matter how model is animated and how the bone rotates, attachment would always remain at its natural angles)