We identify three possible mechanisms of action, though not all of them are forces that we recognise in modern physics (gauge forces).
The collapse of a boson is a movement of energy: a constituent part of the fermion is displaced to another location.
Although this propagation occurs at light speed for all waves and particles, this does not mean that all particles move at light speed. The path for a sequence of collapses may take a 'long walk', or just jitter around the same approximate point, which reduces the apparent velocity of the particle when it is measured over time. Despite identifying this as 'action', it is not a good description of 'force'.
The direct modulation effect is the displacement that a vacuum modulation imparts on a solution.
|Fig.1: Phase modulation of Z by ρ, giving W.|
When bosons cross each other, the modulators create an impulsive phase shift in the other bosons at the overlap. Using the terms from fig.1, W is modulated by ρ, which is introduced at t1. Had the bosons not crossed, the quantization condition for wave W would have occurred at t2.
This phase modulation causes solutions to be retarded or advanced, so changing the position (and time) of the solution in the vector of propagation.
Typically, this displacement would be tiny, say 10-20 times the fundamental wavelength for a mass of ρ = 10-20. Although this does affect the postion of individual solutions, performing this test across the whole wave cycle would find solutions that are displaced by almost a whole wave cycle, which cancels out the smaller gains [there is detail in the exceptions, which should be explored further].
A statistical tendency of a conserved fermion's bosons to collapse towards the sources of vacuum bosons, is the mechanism for gravitational force.
It is also the origin of charge-based forces, as the displacement effects of organised structured sources (classical bodies) that direct currents of vacuum energy. Both these forces have equivalent nature, as a gradient of vacuum energy flux.