The idea looks great! 
Also the usage is very simplified, I’d rather start with examples like this, instead of diving into render pipeline and learning everything from scratch. When I was thinking about post-process effects I would imagine something like this - applying a commonly used post-process without really diving into how it is made.
For me, still this is the difficult topic, though I was learning it a lot. I managed to understand thoroughly shaders, but drawing in Defold is still complex at the start 
It was what I was lacking in Defold from the begining - ready lights components, easy normal maps for sprites, fluid simulations, post-process examples like Unity or Godot have. Of course, I’m not taking into consideration 3D features, because I was looking for a 2D engine. Naturally, those brainless modules do not force you to learn and I think I must be grateful for that in Defold, though still, for the beginners it’s something that allows to judge the engine, unfortunately.