[Proposal] Standard Address Upgrades

(an adaptation of Zcash Unified Addresses (ZIP316))
This is an extension of social consensus, compatible with PBS.

PBS introduces a stakeholder set, whose signatures are required to progress each rollup. Because PBS allows stakers to run on low-end hardware, it is acceptable to assign a single stakeholder set to multiple concurrent rollups.
The PBS stakeholder set is then assigned, via social consensus, additional rollups as needed.
If a rollup’s based block rate is consistently and considerably higher than its staked block rate, it transitions into a based-only rollup.

Unified Addresses: Adding a new rollup

Once social consensus has been acheived, a new address type is added to a Unified Address standard, like in Zcash.
The unified address format is a concatenation of multiple Aztec addresses for different protocol versions.
See Zcash for a complete example.

Removing a rollup

If a protocol becomes deprecated (e.g. a vulnerability is found), the address type is marked deprecated in the standard.