If you buy a primer pocket crimp removal tool, you don't really have to "see" the crimp, you can feel it as soon as you put the tool into the pocket.
This makes it easier because you don't need to pre-sort the brass, I just work my way through all of it because as soon as I put the reamer into the primer pocket I can tell that the case doesn't need it and I just drop it in the done bucket and move on.
Obviously, if you're using other methods, you need to know which are crimped so you don't over do it.
When I need to, I can do hundreds of cases in an evening. It's just not that hard, even when doing it by hand.
Grouse