If you are worried about hitting the edge with the loupe. Here is what I do with my Carson, Mico Max, add a piece of foam to the contact edge. “
Show the World How You Modified Your Tools”, (post 78), a great thread packed full of tips.
The foam protects the edge and after a while cuts a notch in the foam that makes registration of the edge for focus easy.
If you want to slide the scope down the razor, lift it off the edge or bevel and hook your pinky over the spine as a guide, slide the scope down the bevel, with it off the bevel and drop back onto the bevel when you stop, you will be in focus or very close and no danger of the edge biting into the scope and damaging it....