Multiple banks simply refuse to have custodian accounts and will offboard you if they see money coming from a crypto exchange(too much KYC). I checked 6 months ago last, but PWC did not offer crypto auditing services at all, so if you are audited by PWC you would need to switch. Setting up any sort of reasonable operational infrastructure (cold storage solutions, access) was completely impossible 6 months ago, now places like Copper would probably kill to have your business.
From personal experience any actual crypto exposure that was taken on in small-medium hedge funds was by literally having a trader set up a private account and just message the exchange and try to convince them to get access to institutional products, if they even wanted that sort of leverage. It used to be that much of a hassle operationally.