The current configuration structure for linking terrain surface types (CfgSurface entries) to particle effects that are created when entities move over it is not patchable through addon files.

Currently as it stands the CfgVehicles classes Car, Tank, Air and Man have two parameters, rightDustEffects[] and leftDustEffects[], which are arrays. These arrays contain nested arrays that are pairs of cfgSurface classnames and their linked particle effects.

This array cannot be extended by community addons, thus creating a problem where there can only ever by one addon loaded that redefines these arrays to inject their own surface definitions.

Solution:
The config operator "+=" would be the way to go here, however that operator can not extend arrays with nested arrays:

rightDustEffects[] += { {"Nested","Array"}}; // Does not patch the array.

The easiest fix to solving this here would be expanding the += operator to allow adding nested arrays to the array-parameter. This would not cause any issues with backwards compatibility.

Alternative Solution:
Changing the config structure of this into subclasses:

class rightDustEffects
{
    surfaceClassname = particleEffectClassname;
};
class leftDustEffects
{
    surfaceClassname = particleEffectClassname;
};