You could switch the road BB cups to mtb BB cups. That would make the overall BB width 2mm shorter, and bring your chainline 1mm inward. You'd have to shave the plastic stops on the water sleeve so that they'd fit in between the mtb BB cups while on the narrower BB shell. The left crank arm probably has enough tolerance to eat up the extra 2mm of spindle protrusion, and you get 2mm narrower q-factor.