I've got a couple of these Kipon milled adapters - they both mount a lens rotated at 90 degrees to a proper mount. I also have a Milich adapter and a CV type II adaptor - these both mount a lens correctly.
In general, the Kipon adapters focus and couple with most lenses correctly. When coded, my M8 reads the milled Kipons accurately. HOWEVER, the 90 degree rotation causes two issues that a buyer should be aware of:
1) On LTM lenses which are able to do coupled focusing at less than one meter, the extra 90 degree roatation generally means that they will be uncoupled when focusing below one meter. These are generally the modern CV (and Rollei) lenses which have a cut out where the focus coupler of the camera sits (when mounted properly). Lenses that I have experience with which have "close focus coupling issues" with the Kipons are: CV Ultron 28/1.9, CV Nokton 50/1.5, and the Rollei Sonnar 40/2.8. The Militch and CV adapters do not have these "close focus coupling issues".
2) On LTM lenses which couple focus with the camera via a tongue will also have focus coupling issues when they are rotated 90 degress to a proper mount (chances are, they won't couple focus at all). These are generally 90mm and longer lenses from all manufacturers. Leica, Canon, Nikon and even the modern CV APO-Lanthar 90/3.5 all have used tongues to couple focusing. Again, the Militch and CV adapters do not have this problem.
All that said, I've just ordered a couple more milled Kipons for lenses where I know they will work correctly 🙂