Thoughts on Block-Fi?

Hello all,
I was just curious what the community thought about using Block-Fi in general and as alternative to staking. My company is considering using them to get a flat APR over a lockup period on our Ethereum, but we had a few concerns and were just wondering what the general perception of them was.

Specifically, we were wondering how they lend Ethereum and achieve staking awards while being able to return your Ethereum at the end of the period? Isn't any Ethereum used in staking locked until the Shanghai update? How are they accomplishing this?

It's also somewhat similar to Celsius in its business model. What do you guys think about its similarity to them? Any similar risks they decide to lockup people's assets when they can't pay bills? Any other risks unique to them?

Finally does anyone know what happened to the people who led Celsius. What are they doing now? We were wondering if they might have been absorbed by companies like Block-Fi?

Any thoughts are appreciated!