Fusion's help file defines timer-based movements as:
I'm wondering why doesn't this apply to the physics engine? When I run my game on different devices, the impact of impulse (movement --> physics --> add impulse) is vastly different depending on the overall performance. Basically, on devices with lower FPS, the impact of incremental impulse added to physics objects is greater.Timer-based movements
When this option is selected, the movement and animation speed of the objects in this frame is based on the exact time difference, making it independent from the machine speed.
I have timer-based movements enabled in the frame properties, and also tried the old machine-independent speed option.