By default, I always use those settings:
-Min:-1, Max:2
-Treshold: 0.05 everwhere
-Filter type: Gaussian 3/3
If some parts flickers, then I use:
-Min:0, Max:3
-Treshold: 0.025 everywhere
-Filter type: Gaussian 3/3
If there is still some flickering, then I use:
-Min:1, Max:4
-Treshold: 0.01 everywhere
-Filter type: Gaussian 3/3
There are cases where flickering is not related to anti-aliasing. For example, if you have an horizontal line that is in contrast with the background, it might flicker, whatever anti-aliasing settings you use. Worse, if this line has a thickness of less than 3 pixel, you're in troubles.
Also, Final Gathering oftenly results in some flickering noise. You have to crank up the min/max radiuses to get rid of it.
Hope this helps
Salutations - Cheers
Bernard Lebel