[BIP-451] Enable wstETH/rETH/sfrxETH gauge [Optimism]

PR with Payload

https://github.com/BalancerMaxis/multisig-ops/pull/547

Summary:

This pool uses the composable stable pool factory v5 and contains three unique staked ethereum tokens, staked frax eth (sfrxETH), wrapped staked eth from Lido (wstETH), and rocket eth from Rocket pool (rETH). As most Balancer community members know, rocket pool and lido have become pillars of the ecosystem through the use of the metastable / composable stable pool types to leverage their yield bearing assets. Staked frax eth will be joining these two juggernauts to facilitate trading and LPing amongst these diverse staking strategies of ETH. This gauge would enter as a “core pool” under BIP-19, meaning protocol fees earned by this pool would be used to bribe for votes on it.

References/Useful links:

(sfrxETH) Link to: • Website • Documentation • Github Page • Communities (wstETH) Link to: • Website • Documentation • Github Page • Communities (rETH) Link to: • Website • Documentation • Github Page • Communities

Protocol Description:

sfrxETH is a Frax’s staked wrapped ETH token, wstETH is a wrapped staked ETH token for Lido, and rETH is the staked ETH token for Rocket Pool.

Motivation:

Balancer is clearly pushing forward on all networks with staked assets as a key focus. By diversifying the protocols which supply staked assets Balancer opens up the door to liquidity providers to gain exposure to multiple providers, while facilitating trade routes for these assets. The protocol benefits greatly from yield bearing assets, and Balancer’s users do just as much. This pool will be a unique and diverse group of Ethereum assets making it exciting for everyone involved.

Specifications:

1. Governance: Find more information about governance on each projects forum. sfrxETH , wstETH, rETH
2. Oracles: See each rate provider contract linked here respectively sfrxETH, wstETH , rETH
3. Audits: See sfrxETH, wstETH, rETH.
4. Centralization vectors: Rocket Pool is a protocol for decentralized and trustless ETH2 staking. For Lido and wstETH please read here. Lastly for FRX and sfrxETH see here.
5. Market History: See rETH, wstETH, and sfrxETH
6. Value: Balancer will earn the protocol fee on all assets in the pool and so will LPs. The BIP-19 flywheel will incentivize TVL to grow here with trading volume and our staked ethereum pillars will continue to have Balancer as their ideal liquidity destination.

Link to pool: https://op.beets.fi/pool/0x5F8893506DDC4C271837187D14A9C87964A074DC000000000000000000000106 Link to child gauge: https://optimistic.etherscan.io/address/0x5669FB0DCfA758Bf69FB3AdAB14578EDe14cc89A Link to root gauge: https://etherscan.io/address/0x6A2C2d4502335638d2c2f40f0171253fb2c2db88#readContract

Specification:

The Balancer Maxi LM Multisig eth:0xc38c5f97B34E175FFd35407fc91a937300E33860 will interact with the GaugeAdderv4 at 0x5DbAd78818D4c8958EfF2d5b95b28385A22113Cd and call the addGauge function with the following arguments: gauge(address):0x6A2C2d4502335638d2c2f40f0171253fb2c2db88 gaugeType(string): Optimism