Get a Metal Desk and screw it to the Ground.
For Example
Doesn’t really help I’ve never found a desk that doesn’t shake for osu let alone using stroker devices
If your chair (and/or desk) has adjustable height, something that may be worth trying is sitting as close to desk height as you can and resting your legs from the knees down on the desk.
Might not be to everyone’s preference, but it’ll make your body attached to the desk in a way that could reduce the shaking and make the shaking less of a negative 
You could consider a pole-type monitor mount inserted into a heavy outdoor umbrella stand. That’s what I’ve been doing for a while now, and it handles fast scripts just fine. It’s just a question of where you keep it when not in use. I just shove it under my desk, but that might not work for you. The kind of chair you’re using also matters, and the shape of the stand. With a typical five-leg rolling chair and a round stand, things work out for me.
…and this is why i use the bed!
But seriously, your issue comes from the fact you’re attaching the mount to the centre of the edge of a flimsy desk, as far from the suspension points (the legs) as possible.
So you could either…
Move the mount to where a leg is, at the corner.
Attach fifth leg directly under where your mount is.
Screw a thick heavy wooden board into the underneath of your desk, that stretches from leg to leg.
Get some heavy thick blankets, or heavy cushions, and put your weights on these, you need to absorb vibrations, it’s not just about weight.
Any number of the above.
Or as Thanny above just said, mount the whole thing on something separate from the desk…
The easiest fix is getting a stool or something that isn’t a table and mounting the device onto it
I also experienced a loudly shaking desk while using the Funsr1. I was just using two metal strips welded to a backplate which is screwed to the Funsr1. The contraption is then slid and held by friction, in a holder under the desk. I also use this completely invisible holder to attach a steering wheel to the desk. Decoupling the holder from the Funsr1 solved the shaking problem for me. I used medium stiff silent blocks attached as seen in the Pictures. It´s a crude construction but it not only cut the noise generated in half but also left the desk completely still. As i only had medium stiff threaded silent blocks at hand the Funsr1 is tilting quite hard with very fast movements from the script. I thought i might just attach a third “member” to counteract this tilting motion around the Fulcrum but instead gave it a try. While using, this tilting motion is counteracted by a pleasant smack to the balls. Intrigued by the concept i quickly draw up a testes tickler in CAD and 3d printed it. The thing just clips to the bottom of the Funsr1. It is a two part design, which lets you experiment with different business ends. I upload the .stl´s and i encourage veryone to give it a try. While the damping of the silent blocks is quite high, the system will resonate. When the script is around the resonance frequency the tilting and thus the hits to the balls are harsh. Nowhere near actually hurting you, but be warned.
