MX MASTER3-3S NEW SHELL

New model with the same objectives:
   1: The thumb does not need to leave the shell's support to activate the 3 buttons on the right side.
   2: The upper button is activated simply by extending the index finger and lowering it. (A slightly extended index finger is enough to avoid activating the left click when pressing the button.) 
Advantages of this new model:
The positioning of the shell on the mouse body is improved.
The hold of the shell on the mouse body is improved with an added tab.
The side buttons fit well, the clearances have been reviewed and the shapes of the guiding elements have been redesigned. Nothing to file or adjust; once the shell and button parts are free of all support marks, assembly is easy.
Once assembled, the buttons are in good contact with the mouse buttons, without excessive play. 
The lateral support for the pinky and ring finger has been extended forward but slightly reduced in width, which is sufficient and a little less bulky.
The finger contact areas on the buttons have been rounded, and the upper surfaces have been angled. You will see that operating the side scroll wheel is greatly facilitated.
If you make this shell, feel free to say so and share your impressions. Perhaps there are different button shapes that might better suit certain users.
Here it is..
You can watch a short video: