Yes, Kawasaki used the 46019-0001 throttle grip on all the ZX-10R's all the 14R's, most of the 636's, the 6R and the 6RR's
but as I've said in the past the R6 grip only reduces the throw about 10' degrees. Stock is 90' degrees, with the R6 grip it's about 80' degrees, with my 1/5th it's 72' degrees.
the other thing is that the R6 grip is about 1/2 an inch shorter then the Kawi grip so there is a visible gap between the grip and the bar end weight.
the rubber is also different so your grips are mismatched or you need to get the matching rubber for the other side.
this is a great mod for a track bike where you aren't worried about the gap or grip mismatch.
If you want your 10R to keep it's factory look but upgrade the throttle response, the insert is the way to go.
I honestly don't recall any of the issues you're describing when I installed the R6 grip on my ZX6R. Maybe it's different in the 10 who knows. But the rubber grip I swapped over from my after market grip so ther was no issue there and I don't recall a 1/2 inch gap. Based in the size of the throttle tubes I would think it was a lot more than 10 degrees. The responsiveness was significant imho and there was less wrist fatigue when i rode. Maybe I have a picture laying around somwhere.