You edited the post to add the pictures later.
I was saying there were no pictures in the post when I saw it.
I think this area is the weak spot and where alot of "flex" and vibration is transferred.
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And I think adding a small thin(3-4mm) silicone block/strip between the top frame and where those circle dampeners meet, it would help with cancelling or minimizing vibrations that get transferred to the lower half of the quad. You would need longer screws that hold on the dampener, because now that screw would need to be long enough to go through the thin silicone block, through the quad frame and then into the dampener.
View attachment 19136
View attachment 19135
somthing like this block but a small thin strip to fit or be sandwiched between the two pieces. Thats my solution to help cut down on vibrations coming from the motors, props, etc. And keep it minimized...just less transferring to the lower half of the quad and into the load pipes and then into the gimbal. It will act as a little rubber footing, or silicone whatever....