Hi Daniel,
On one hand, that -blur_opts_BIM option is missing an internal step for applying it. I will fix that.
On the other hand, neither of those options is appropriate for being passed via -blur_opts_BIM. Basically, options passed that way in general should be ones that afni_proc.py does not (need to) know about.
The blur size should be specified via -blur_size.
But there is no mechanism to blur in only the gray matter, or to specify the blur mask via a generic lablel. Relevant options might include:
-blur_in_mask yes
-blur_in_automask
-blur_size SIZE
-mask_epi_anat yes
- rick