SSS will transmit GI light, but it only seems to work with the Quasi Monte Carlo GI method. All in all it would be dreadfully slow if you want to get a clean result. I’m not familiar with the MR shader you used but if it works, and this is something you do all the time, that may be the way to go.
I just had a play with Octane Render in Cinema and it does a nice job surprisingly quickly, but that’s another cost and it requires at least one decent NVidia card.