How to get index of collided instanced static mesh?

Is it possible to get the index of a collided static mesh, or, do i have to hack it in somehow?

Yes, you can get it through the Hit Item parameter from Hit Results. If it’s an object collision, then you can use the On Component Hit of the Instanced Static Mesh for this.

Or if you’re using Line Traces, breaking the block hit result will also give you the same result.