I just did a little modification on my Amago rod grip by sanding it down some and rounding it off a little more at the front edge of the grip. I like putting my first finger on the rod blank because I feel the rod is more sensitive and transmits more information into my hand that way than with my finger on the cork, and the sharp edge of the grip was a little uncomfortable and too big of a step down to the rod blank with my hand in that position. Now it is fine.
I also compared the diameter of my Amago rod's grip to some of my western fly rods and my Iwana rod as well, and all the rods had similar diameter grip measurements, but with considerably more taper to the cork at the front end of the grips on the other rods, whether they were western or Tenkara fly rods. I recently got to cast a friend's 11 foot long, two or single handed grip, 7 Wt. Switch rod while I was fishing with my Amago rod. The Switch rod was cast with an Airflo Speydicator Line, which weighs 490 grains over the first 31.5 feet of its length, which is actually a 14 Wt. fly line in true grain weight. The grip on that rod was noticeably thinner than the grip on my Amago rod is, and that was before my modification to my Amago rod grip. My glove size is a large to an extra large, depending on who is making the glove being tried on. I found both rods to be very comfortable to cast.
I also fish with my hand at the back of the grip position on the Amago rod most of the time, but I like to change things up to shorten the rod's effective fishing length when needed, and also to lessen the leverage and the perceived weight of the 13.5 foot long Tenkara rod by bracing the grip against the underside of my forearm for a while with my hand in the forward hand position on the grip, first finger on the blank, all of which has worked out to be much more comfortable for me with the little bit of sanding down of the front end of the grip that I did. So I don't see Daniel's not offering the add on handle option to be a big problem for most of us. A little sanding might improve your Amago rod as well if you have similar sized hands and you use your rod in similar ways. If and when I buy an Ito rod, I will make the same grip modification to the Ito rod as well....Karl.