They make MLS gaskets as thin as .027" for SBC with a 4.060" bore. I think that's about as thin as they get. They offer a large variety of thickness to taylor quench and compression. It's a great gasket, I've used them before on LS builds here, but I considered them overkill for my little 302 build when I could use a standard gasket that gave us exactly the quench we were looking for at half the cost, thanks to putting the pistons close to zero deck. Bischoff recently used MLS gaskets on my fathers 571 pump gas street engine though. Only 10.84:1 compression on that engine but Tony doesn't mess around.
I'm not sure exactly what you are working with Deadmetal, but if it's a factory deck height block with factory internals you can bet the piston is going to be .020"-.025" in the hole minimum. Even with the steel shim GM head gasket at .015" these engines when they are virgin don't have the 11:1 compression they advertise (mine didn't) They usually fall a tad short. So in that case I agree, I wouldn't want a thicker head gasket on there. It lowers the compression more, but also hurts quench and can possibly make the engine more susceptible to detonation if it's tuned on the edge.
The old thinking was putting thick head gaskets on an engine with high compression was the way to make it tolerable. But smart engine builders quickly found out that was a bad idea. Especially when dealing with dinosaur cylinder heads with poor combustion chamber design.