gaiacli keys show <multisig_key> should show constituent pubkeys, and their weights.
This would likely require adding a new multisig keytype to the keybase.
Additionally, gaiacli tx sign --validate-signatures with a threshold multi-signature should show which subkeys signed the transaction, and their weights, in addition to showing the validity of the composite signature.
I can pick this up.
Additional thoughts from @cwgoes:
--chain-id in the CLI, it defaults to empty string sometimes
Most helpful comment
Additional thoughts from @cwgoes:
--chain-idin the CLI, it defaults to empty string sometimes