I have had some spills with the Pocket Rocket.
As a user, I can safely say that each of the spills was my fault in not seeking a stable base for the stove/canister in the first place.
I bought a different stove, subsequently, and with the same canisters there hasn't been a spill in over 100 uses.
Reason, I earned the importance of MAKING a stable platform for setting up the stove/canister from my previous mistakes.
You may want to consider things like the commercial 3 point holders for the fuel canister - the famous three point stable base.
Or you might think of stomping a flat area in the dirt with your boots, or use of your potty scoop for "ground engineering", or picking up small slivers of wood or twigs to remove the wobble from however you have tried to set up the canister/stove on a non-flat surface.
I believe it is possible to set up an otherwise stable item unstably with careful selection of setup location.