1) Do we need to send just one damper proposal, or can we send a backup proposal for a different damper in case our proposal isn’t accepted? 2) Are dampers included in the structure weight? 3) Is there any material that is prohibited to be used in damper design?

We will post the requirements for the damping proposals soon. Meanwhile, here are the answers to your questions:
1) Sure, just inform us which one is which one so that we just review the backup proposal in case the first one is not accepted.
2) For scoring purposes, the Structural Model Weight, is equal to the weight of the structural model including damping devices but ignoring the weight of the floor dead loads, roof dead load, base plate, and roof plate (Section 4.4).
3) Any material is allowed to be used in a damping device.