The heart of the matter is that before there were finished points, there was flakes and flake scars. And, before there were flakes and flakes scars, there was flaking technologies.
The heart of the matter is found in the flaking technologies, themselves - not in flakes and flake scars, and not in finished points. The heart of the matter is found in the actual flaking technologies, that were used by people in the past.
Those who reject the study of flaking technologies reject the source of historic/prehistoric flakes, flake scars, and finished points. That is the heart of the matter.
As far as "notched flakers" are concerned, 99.99% of antler flakers found in the New World archaeological record, appear to be unnotched. There is probably a less than 1% exception, though, because at least one of the tribes, in the Northwest, appears to have used a notched tine flaker, at some point, during the historical era.
Also, in working obsidian, Ishi's explanation for his preference of a steel tine flaker, over an antler flaker, may just shed some light on why not many full sized tine pressure flakers are seen, in the archaeological record, in spite of the fact that there photos of historical Indians demonstrating pressure "re-touch", with said flakers. For those who think this through, the question that out to be raised is whether "retouch" and "manufacture" are really the same thing. And, if not, then were other types of pressure flakers used during manufacture? Obviously, there is strong evidence of composite bit pressure flakers, being used throughout the historical era, and prehistoric era, across the continent.
Regarding your example of a copper bobber outré passé flake, in presumably heat treated chert, I can make almost the identical flake, in raw chert, with a hammerstone:
Plus small initiation:
If a person knows the right hammerstone technique, then he can make these types of hard hammer outrepasse flakes, all day long.
But, hammerstone percussion is not necessarily the same thing as late stage thinning, in raw materials.
Also, the same unnotched deer tine that is used to create outrepasse flaking/coast to coast flaking is the very same unnotched deer tine that can create other types of flaking, such as the central rippling seen on the Sweetwater biface. Here is the proof:
Central Rippling in Raw chert:
Here is a shot showing central rippling being produced:
Here is from the back edge:
Here is after removal:
and,
Here are the central ripples on the Sweetwater Biface:
Still, the same technology that produced central rippling in raw chert, also produced the following overshot flaking, in raw materials:
Same process - Totally different outcomes. One process - different results.
So, I can show that a single process can create a range of mid-late stage flaking effects, in raw materials. And, I can carry out the process in areas where other tools will not reach.
So, why would Clovis knappers, and paleoindian knappers, "reinvent" flintknapping, if a single technology can produce an array of effects? Outrepasse, coast to coast, fluting, central rippling, trimming, flaking, etc?
Also, there is no mystery to this. The evidence was presented to many hundreds of people in the flintknapping community, in the fall of 2010, 2011, 2012, 2013, and 2014. Steve Nissly and his protégés can attest to this.
So, for all of the dozens of people who demanded to see "proof", you can see the tool - a simple unnotched flaker. You can see the materials - a full range of uncooked stone. And, you can see the results - outrepasse, centralized rippling, coast to coast, fluting, plus the more generic forms of flaking.
Now, there is no more mystery.