Drop Shadow post processing effect?

Hey guys,
I’m after a post-processing effect similar to Persona 5’s victory animation.

I know I should make a post-process blendable material, using a custom depth mask to isolate the meshes I want to have a drop shadow.
But other than that, I’m not sure where to begin.
Are there any tutorials or example content similar to this effect that I might be able to learn from?

This is the only info I could find on a Drop Shadow in UE4:

You can get it by subscribing to the guy’s patreon for $8:

Or on the Marketplace: