Greetings,
I ordered a MOARStruder (Opah) which has an awesome extruder brace. You can see it below behind the wiring harness:
It connects above the motor to the screw hole and reduces play at the hotend.
I’m currently printing three sets of the extruder_body and extruder_brace, going to order some brass fittings and should be able to stiffen all of my toolheads, including the duallys:
http://devel.lulzbot.com/TAZ/accessories/opah/production_parts/printed_parts/