Hey @RyanB,
No problem at all man! You’re a tech artist at Epic so I’d imagine you’re pretty busy. I’m happy for any time you can make for us on the forums here. 
Ohh so that was what you meant regarding a separate custom material! I was thinking that you meant a custom node in the Volume decal material, but was confused since that was what I was already doing.
That makes a bunch of sense. I’d have to write the raymarching code again, but whatever at least I’d have more control over it that way!
Also will replace those two functions. I think precision issues wouldn’t be a problem cause I don’t require super detailed results or anything. These are for gameplay usage (hopefully) and the player won’t ever be looking too closely at them.
I don’t suppose there are any plans to expand Volume decal functionality? It’s quite a cool piece of tech so I’d be interested to see more features added to it.