Into MinecraftForgeClient.java:

 

    public static HashMap<String, EntityFX> customParticles = new HashMap<String, EntityFX>();
    
    public static void addCustomParticle(String name, EntityFX fx)
    {
    	if (customParticles.containsKey(name))
    	{
    		return;
    	}
    	customParticles.put(name, fx);
    }

 

RenderGlobal.java

 

public EntityFX func_72726_b(String par1Str, double par2, double par4, double par6, double par8, double par10, double par12)
    {
        
                 ...

            if (par1Str.equals("hugeexplosion"))
            {
                this.mc.effectRenderer.addEffect(var21 = new EntityHugeExplodeFX(this.theWorld, par2, par4, par6, par8, par10, par12));
            }
            else if (par1Str.equals("largeexplode"))
            {
                this.mc.effectRenderer.addEffect(var21 = new EntityLargeExplodeFX(this.renderEngine, this.theWorld, par2, par4, par6, par8, par10, par12));
            }

            // New:
            
            for (int i = 0; i < MinecraftForgeClient.customParticles.size(); i++)
            {
            	EntityFX fx = null;
            	fx = MinecraftForgeClient.customParticles.get(par1Str);
            	
            	if (fx != null)
            	{
                	this.mc.effectRenderer.addEffect(fx);
            	}
            }

                 ...

We DO have a github, submit a pull request there, if you want to submit code.

So you propose we add support for a single EntityFX.. Look at what your code is doing....

But, either way, if you want your custom particles, just spawn then directly, dont go through RenderGlobal.