I think most users…er…artists will generally not adjust step size and if they do they will lower them and they will be put off with the longer render times.
However very often a lower step size IS essential. It is all very well getting ‘fast’ renders …but if they look poor then why bother. Here are 2 examples the first is at the default step size and the second lowered by a factor of 10. The render times went up by 2x and I think that render hit is well worth if for the quality.
I am using my 8GB GPU scene file you can find in my benchmark post
Note this is using a BCF file with an Arnold tag on the TFD container which defaults to a step Size of 10. If you convert to VDB the Step Size is set to 1. So VDB may not need adjustments.
You can d/l my 13 hour TurbulenceFD tutorial set from here