Why after inserting emitter object in display group and scaling this group, particles do not change their sizes, distance between particles are changing only?
User are zooming location there are explosions animated by particles and its will not be scaled. At best way, particles will not change the size at all and will not match the size of other objects in the location. In the worst, animation will be spoiled due to distance change between particles.
Why not make the emitter behave like a simple display group?