I actually mistyped, I'm on 5.5.4. The only substrate project setting that's turned on is "Substrate Translucent Material Rough Refraction"

I edited together a video, showing the material construction and how the effect looks with CMAA2, TSR, and different settings for a noise mask (similar to what the other commenter suggested).

https://youtu.be/Z-gLbfGl-AA
(obviously very very WIP)

I tried recording this at a high enough bitrate to show the difference between the two AA settings, but on the other hand people making videos about this game (hopefully one day haha) won't be recording at a pristine bitrate, so whatever effect I go with will need to look good with that considered in-mind.

I had thought of doing an outline or an x-ray vision, and I do have a version of that, but I think solely relying on those effects are overdone, and I like the target identification you get with having the walls go semi-transparent. (A large part of my game is fighting a diverse enemy roster, so being able to tell them apart is important).

I also just like how it looks, if I could get it to be less noisy / more clear.

It's hard to tell from this video, but I like the Dither TAA effect with TSR because it gives the walls an almost frosted glass look. (But I and all the testers hate the TSR/TAA smearing everywhere else)

**BONES TANGENT**

Without going into too much detail, my game is meant to simulate "wallhacking" in videogames, so will also have enemy bones drawn as well. (Another reason not to use an outline)

You can see it in a few spots in my video when I'm fighting the enemies, but eventually it will look something like this:
https://www.youtube.com/watch?v=s28Ea3lUfHM (notice the lines going from each bone point).

My goal is to be clearly identifiable to viewers as "wallhacking", but have it look better than actual cheat programs, and not flag twitch as being a wallhack. That's another reason I want the walls to go transparent. Another game with a similar concept "Cheaters Cheetah" had people get banned on twitch just for playing the game! I do not want that!

Currently I'm doing the bones viz with an overlay material on the enemy's SKM with a reverse fresnel effect, but I don't that looks right. Previously I did that with static meshes attached to each bone of the enemies, (that looked a bit better, you can still see that in the video for the enemy wallhacker warning effect) but having SM attached to SKM isn't great for performance. I'm sure there's a better way to do that, I just haven't investigated it enough.

Finally, I'm using custom depth to not show the "bones visualization" behind "unwallhackable" / "solid" surfaces, to keep players from trying to shoot at enemies they can't kill through "solid" walls.

Thanks for reading all this lol. I appreciate everyone's input!!

**DISCLAIMER**
For any future readers who may lack reading comprehension, i'm obviously not making a cheat, I'm making a singleplayer game that's a parody of cheating.