That documentation you pointed out is currently the material setup for the rasterized method (UE4.21 and earlier) and so far that one works (sort of) for glass. My material setups I usually put a fresnel node going to Opacity and if the glass should show the inner side, I use double sided material, so I can fake thickness. More thickness to glass, above 1mm, would require a mesh like you described earlier, having an inner mesh with normals respecting the surface continuation from outside.
My expectation is that 4.23 with the adjustments in the translucency we can rely on the same material method used for rasterized or have anything extra in the settings to make it like the other renderers work such as VRay.