next vveekend vvorkshop will be about geometry in dx11 and this will be also covered.
in dx11 the geometry is only a dumb stream of bytes with some metadata attached to them and in theory there are no mandatory semantics like in DX9. even there can be geometry which doesn't contain any data (NullGeometry) or a geometry which contains a single number per-vertex with a semantic called KITTYCAT. dx11 doesn't even use indexbuffer anymore internally on the gpu.
so to write geometry in dx11 you have to ReadBack the rawbuffer of a geometry via a geomfx or a streamout renderer. Set ReadBack to uint and connect it to asraw and set that to uint32 then write it to disc, i recommend doing that in a patch with exposed evaluate pin because it will take a lot of cpu time. you can also write a metadata file which tells you the inputlayout of the geometry (InputLayout node -> InputElement split node) (it will be necessary during reading the geometry from disc).
reading back is similar read the file you saved before and use AsValue (Raw) set to float32 connect that to GeometryBuffer node. define your input layout with InputElement advanced from the metadata you saved and connect that to GeometryBuffer too. make sure Apply pin is not true every frame.