I strongly encourage another look at @0xDonPepe suggestion to utilize Obols public good DV infrastructure. (1% For Decentralisation: A Funding Model For Ethereum)
With Obol distributed validators the operation and validator keys can be safely split among several decentralised operators.
We can see the effectiveness of DVT from Lido sDVT module: https://obol.org/Lido_SDVT_case_study.pdf
This program utilizes a mixture of professional and semi-professional (solos-stakers) operators and has proven track record or performance against centralised staking pools.
A custodian such as Bitgo could still be used, or a Multisig by foundation in control of the underlying funds, however I strongly recommend outsourcing the validator operation to decentralised set of node operators and not centralised exchanges such as Coinbase or Kraken.
There is a growing problem of staking concentration & net operator penetration, the top 48 operators control over 50% of staked ETH. The situation becomes even more pronounced when we factor in centralized exchanges (CEXs) like Kraken, Coinbase, and Binance, of which only the top 5 CEXs control an additional ~20% of the staked ETH. (source ‘rated.network’)
Obol can offer security and resilience for staking operations as well as competitive rates, with the added benefit of taping into a decentralised node operator set, this is much better aligned with Ethereum and Optimism.