Is the rotation not on a x,y,z set up? Seems like it rotates universally. Also the UI looks off the word ‘Angle’ pops out.
It would be nice to control the rotation based on the x,y,z.
Scale has the same issue in the fx editor
I want to create something like this, but seems a bit challenging with the tools at hand.
The particles in the system are billboarded to the camera so rotation speed graph represents the speed of the rotation of the particle around the axis that is pointing towards the camera.
Looking at the gif, the particle effect is an animated sprite (which can be used in PlayCanvas) so I think you can get pretty close to this effect if you have the sprite sheet.