Sorry if this point wasnât included in the design doc (I thought it was). In any case, it has been discussed and finalized in my own mind that the Bitcoin blockchain would be examined as of a certain block height, resolving the concern raised here.
This is addressed here:
https://bitcointalk.org/index.php?topic=1033773.msg11156623#msg11156623
I will add that shareholders will prefer signers that have pledged a security deposit (in Blockshares), which is discussed in the design doc.
It is expected that the security deposit reputed signers put up will not be released until the keys are verified to have been transferred.
The consumption of a signerâs public keys available as components of multisig deposit address does not occur until they are a top rated signer. They become top rated not by signing but rather by making a public appeal for upvoting. They have to make a convincing case that they should be trusted first.
I hope this answers your question but I am not entirely sure I understand it.
The difference between voting in Nu for custodial grants and motions and voting for reputation in B&C is that it is presumed Nu shareholders can vote for all the grants and motions they want to support in every block. In contrast, it assumed that B&C shareholders will wish to upvote and downvote more addresses than can be practically referenced in each block. The mechanism for selecting reputation votes for inclusion is designed to use minimal blockchain space while still including the complete set of information over a series of minted blocks.