Hi Peter
An alternative to adding a sleve over the dampers to limit movement is to increase the diameter of the rubber dampers and keeping the hight. I went up from D10 mm to D15 mm and reduced the Sh.
I have two 600 14 Pole and one 10 Pole. I find the 10 Pole the most efficient and best suited for the Mejzlik F22x20 and R22x22 propellers. With the D3 ESC the difference is not that big between the motors as with the Mezon ESC.
Br
Henning