Cobalt will bring the following improvements to the B20 token standard:

Pay transaction fees in B20s: as part of our rollout of EIP-8130, users will be able to pay transaction fees in B20s.

Schedule Multiplier Updates: allows issuers to schedule (and optionally cancel) a multiplier to tokens. This allows for onchain representation of splits, without needing to mint or burn tokens. Only available on the Asset variant of B20.

Transfer blocked: simplifies the current freeze and seize model by reducing the burnBlocked + mint steps into a new transferFromBlocked action.

New Policies - Union (||) & Intersect (&&): the Union policy allows asset issuers managing many tokens the ability to share policies by default with the ability to enable overrides per token. The Intersect policy allows asset issuers the ability to compose allowlist behaviors with commonly-needed blocklists.