Microscopes are quite good at inspecting the bevel scratch pattern and looking for bad problems with the bevel. They will tell you little about the actual edge join itself though, until you get a very powerful scope indeed (like, an electron microscope or a very, very good binocular subjective scope.) The actual edge join is also very hard to image well due to depth of field and USB scopes are all but useless for it, with some exceptions I am sure but as a rule, it's going to be extremely hard at a minimum.