Here's an automata that can survive 3-cell edge-chaos.

The three green cells over on the left are python scripted to be randomized every generation. The white cells outside the green area form a structure that can "eat-up" any possible state of that green area, and remain stable forever.

Finding this 3-cell-edge-chaos-robust (a "ThreeEdge") structure was pretty easy. But this is the limit of what I've discovered. Even a 3-cell-CENTER-chaos-robust (a "ThreeCenter"), where the green box is in the center of the grid-universe, seems beyond me. I've been running the attached python script for a while now and nothing is coming up. I've even tried looking for a FourEdge, but no luck. Let alone a FourCenter. So I make this post hoping others will also look. Let's race to find them!!

Pastebin link for the python script:
https://pastebin.com/VVDd7P84
Installing Golly and Python is literally just a few mouse clicks, don't be dismayed before you try.

Mods, this is a scientific topic. Trust me.
And this science is so easy that Anon can do it from his laptop.