Submitted by kenzo
EthAnchors docs state that the contract address of ExchangeRateFeeder may change as adjustments occur.
BaseStrategy does not have a setter to change exchangeRateFeeder after deployment.
Inaccurate/unupdated values from exchangeRateFeeder when calculating vaults total invested assets.
While the strategys funds could be withdrawn from EthAnchor and migrated to a new strategy with correct exchangeRateFeeder, during this process (which might take time due to EthAnchors async model) the wrong exchangeRateFeeder will be used to calculate the vaults total invested assets. (The vaults various actions (deposit, claim, withdraw) can not be paused.)
The exchangeRateFeeder is being used to calculate the vaults invested assets, which is used extensively to calculate the correct amount of shares and amounts: (Code ref)
EthAnchor documentation states that unlike other contracts, exchangeRateFeeder is not proxied and its address may change in future: the contract address of ExchangeRateFeeder may change as adjustments occur.
 (ref)
Add a setter for exchangeRateFeeder.
ryuheimat (Sandclock) confirmed 
