How to use Atlas splitter and scatter nodes?

1. I did a perfect 12x12 square cells atlas     but  the "splitter" shows me nothing at all ?  Should I do something special to make it work? 

2.   Atlas scatter  works but  makes the alpha/opacity  kind of  binary  . It strongly degrades the quality of detais  and I have to do it in 8196x8196 resolution .  It still doesn't help much although.  Is there any workaround for this?    

Itried to use pre-multiplied  alpha  and it results in  black halos , tried un-premultiplied and put actual anti-aliazed alpha into metall channel  . Alpha goes through with same black halos .

Is there a way to use Atlas scatter properly or  super high resolution is only way?