We already have a concept to deterministically derive a safe address based on (owner list; threshold)
Turning this into a proper EIP would enable a lot of use-cases:
Easier access for DAPPs to assets in proxy SKD (1/1 Safe)
Dapps like Omen are using the proxy SDK and are holding assets (e.g. conditional tokens) in the proxy Safe. When logging into another DAPP (with the EOA) (e.g. Conditional Token Explorer) this dapp just checks for assets on the EOA - with this EIP dapps could check by default for assets in such a user-controlled Safe
For privacy reasons people are using different accounts derived from the same seed phrase.
Today it is a very high effort to create different safes without creating obvious links.
With the proposal above it would be fairly easy to create a tool that lets you import the first n EOA addresses derived from e.g. 3 different seed phrases and then generate the addresses for n 2/3 Safes.
Once gas can be paid from the safe with a relay service it increases the practicality tremendously.
It makes all kinds of nested Safe setups more practical.
E.g. the proxykit can be used with a 1/2 setup instead where 1 owner is the EOA can the second owner is a not yet deployed safe with also 1/2 with again 1 owner the EOA and the other some recovery logic.
Such a EIP can allow block explorer to enrich data.
many use-cases we have not yet thought of.
One open quesion are multiple networks. Is it desirable to be able to create the same Safe on multiple networks (e.g. Ethereum/ dDAI) - or should we even actively try to prevent this?