I'm creating a frame of structural members in SW 2015.  The way I have it set up, Group 1 is the four members at the top, Group 2 is the three members at the front, and Group 3 is the three members at the back.  Within each group, the members are mitered at the corners.  And group 1 trims groups 2 and 3.

The problem is there are small protrusions because the members of 2 and 3 are not fully cut by the members of 1.

If I was forming a simple end butt between two members, I know there is an option to not allow protrusions.  But I'd like to apply that to the automatic trimming between groups.  Any ideas?