Fixing splash damage going through blocks?

Alright so I did a bit of thinking and I'm wondering if, since Facepunch can't get their head out of their ass on that one, we could write a plugin that would make splash damage only work on blocks that are in direct line-of-sight with the explosion.

I assume here that when OnEntityTakeDamage is triggered, we have the explosive position and the block position, so we could make a RayCast to see if anything is in between. I never used RayCast, I think I know what it does, but I figured I'd ask fellow devs on this one to see if I'm going straight for a wall or if I'm on to something..?

I'd also like input on how everyone would fix the rocket vs C4 issue.. I'm thinking increasing the cost twofold AND making the change above would make them pretty balanced and that's what I'm going for.