Multisignature (2 of 3) withdrawal keys for staking could enable collateralized lending while staking

I was thinking how great it would be if banks allowed for stakers to collateralize eth positions, but currently there is no way to do so without a redemption token being created for staking, which does not exist for ethereum staking.

This could be resolved by the system implementing a 2 of 3 multisignature withdrawal system whereby the staker holds one key, defi system retains the other key and a 3rd party acting as a dispute mediator holds the 3rd key.

This would (currently) only work with centralized lending providers as defi versions of lending (liquitiy) require active troves holding the underlying asset to be used as rebalancing mechanisms and to freely liquidate positions that become under-collateralized.

I know that this would be a higher risk scenario for banks because the funds are tied up, so the rewards would be less, but I would be more than happy to collateralize staked funds to get a loan knowing they are locked up, safe, and generating staking interest that will pay back the loan interest!

Reddit, let me know how dumb this idea is :)