Can you describe for me what you mean by "more hammer"? I know I've asked you about this before, but I'm still not getting it.
Let's have another go at explaining this. I think about it quite often, because I want it to be explainable.
Sitting in a meeting today it occurs to me that this might explain it.
The final arc that gets added to the release is the hammer blow.
The arc is easiest thought of as the 3-4:00 pull, that is going to transform the system. The disc to this point has been moving forward into the right pec, then moved forward as the forearm extends about half way - but the timing hasn't kicked in yet to multiply the speed.
Mental imagery thought exprirement:
With the grip at 3:00 on the disc, how would you throw the BACK of the disc (the 6:00 part of the disc) forward?
You would have to hammer that disc from the right edge of the rim. at 12-3:00 the disc goes from behind your hand to 4:00 being hammered forward.
Specifically at F, on the image - the 'handle' on the disc, see how it's rotating forward?
I'd suggest finding a post or a something you don't mind smashing and a disc you don't mind potentially damaging and slowly extend the disc so that you would be hammering a nail on the left side of the post.
had to draw this... too hard to explain:
What seems to change from a standard half-hit or slip is how much of the acceleration happens between 3-4:00 and so there's this point in your work where you have to move however slow you have to go so that you are able to know that you are getting the final arc.
Moving fast will make it probably 500% harder to hold through the hit. Once you get the feel for this micro window of the last hammer arc, adding speed back into the system becomes slightly more reasonable.