This is more of a note for the future, as we don't have transfers yet, but given the long period of time between staking and any potential exit there is a fair chance that at least some users' withdrawal keys will be compromised. It would be nice to give them a potential second chance at retaining their funds rather than them being stolen.

At current there is a VoluntaryExit operation, which moves the validator in to a state where its funds will eventually become available for transfer. If the withdrawal key is compromised you can pretty much guarantee that a 'bot will transfer funds away from the legitimate user as soon as they are available.

If an additional operation VoluntaryExitTo were added (or additional parameters to the existing operation), including a destination for the validator funds and appropriate authorization, it would give stakers a bit more security as both the validator and withdrawal key would need to be compromised for the funds to be lost.