Layering is a goal to make waterhemp fight to get up. In my eyes it’s always good. I have not seen an issue with carryover at 1.5 oz. Not seen a reason to run more. I run a heavier MSO load when I’m worried and I always run 3# AMS with Impact. You will be happier. We cleaned up some heavy pressure nongmo fields with this mix just south of you last year. I always opt to layer group 15 also.