My 2018 Chassis, motor mount and ame back bone came in sooner then I thought :O I already installed the chassis and brace last night. Will update with pics later to give a better view of the brace. Massive difference with much less flex over my old set up, can't wait to try it this weekend.
For reference
2017 Alum chassis 89G
2018 Alum chassis 99G
2017 Motor mount 10.8g
2018 Motor mount 15g
Ame alum back bone 3.7G
So I basically gained 10G on the chassis which I am fine with, the motor mount and back bone cancel out. I usually have to add weight.