I just received my M.2 riserlets, and I've made some pictures here:
https://photos.app.goo.gl/Xuiqj3m3tFXij1VS9 (public; no Google account required).
So, yes, that fits, but 80mm only. The SSD I put in is not the one that I will eventually be using; this rather slow client SSD was just to test that things work as advertised. And indeed: I get the 1.7 Gbyte/s read speed and 680 Mbyte/s write speed according to the specs for this SSD.
A possible issue that I see (though that's due to my mainboard, not due to the riser), is that I will get hard to mount the heat sink and to have it not push against the CPU heat sink.