Consider design changes to the vault to make it more modular

[GriffGreen]

I like the style of vault that dapphub uses: https://github.com/dapphub/ds-vault

They have a system of authorization checks using https://github.com/nexusdev/ds-auth

Their code is poorly commented and difficult to read, but you get the idea. With a series of external calls to short trusted contracts you may be able to better formally verify the contract down the line and it allows for modularity as some people may want some checks and some people may not want it, those decisions can be made when deploying the contract...

The biggest problem is that this creates alot of DELEGATECALLs which costs a lot of gas :-P so it may not be worth it....