Blockfi allows business accounts. But currently they don’t allow withdrawals to a bank account yet.
I have not yet found a way to directly convert business crypto to usd without going through a personal account of some kind.
To keep it completely separated, I’ve just decided to have the business sell me X number of crypto for X number of USD. I pay the business USD directly to the business bank account, and the business than deposits X amount of crypto to my personal crypto account/wallet. And make a note of this transaction.
Best work around that I could think of. No exchanges really do business accounts other than Blockfi.