My 3d printer shook until I secured its table to an adjacent bookshelf with a couple of clamps. Lacking a conveniently placed shelf, adding an anchor into a wall stud and clamping to that would be straightforward.
Vibration isn’t a problem until it is… 
I wonder if it’s better to slow down the score cuts (and adjusting power then appropriately) when you have a lot of changing trajectories in short distances so as to reduce the sudden deceleration.
Hopefully it’s a simple fix either way one goes.
I finally got some help to put a anti-fatigue mat under the Glowforge and locked the casters. They still swivel so the next step is to get some extensions or blocks to use as feet to take the cart completely off the wheels.
Use the glowforge to make stop blocks for your casters! 