Never had a problem using them with high ridges. Sure it is easier without em but those ladies who sit in the back room in tennessee have got real tired hands these days from knapping and covid. Does it really matter how long the cut flints last when they look so much prettier than the hummpy ones? We got no lead mines in this country, we got no black powder plants in this country and we are worried about imported humpy flints. Get a diamond file an file em off. Got a lot more time now since we will not be shooting as much. I think there are bigger issues in this world than humpy flints that can easily be fixed if so desired.
Maybe i should add that the humps do not bother me or slip in my guns because my locks are all on the left side of the gun. You all that put the locks on that other unmentionable side might try them on the other side. They seem to work pretty well on the otherside for me.