Mentor Group Gold
How about this strategy. Let's say you have a net worth of 10MM$
1. 2MM to Swissquate
2. 2MM to SAXO
3. 2MM to INKB
4. 4MM to some private bank
On the broker side, you would pay much fewer fees and if something goes wrong, you would have still access to your money.
You do realize you can have a private bank account and buy investments via a discount broker like IBKR and DFP them to your private bank. That way you don't pay crazy trading fees. However your still likely to pay anything from 0% - 0.25% for custody fees annually.
Maybe I read too much here, but it seems there are cases where bank accounts are blocked until you prove your source of wealth, and that might take a lot of time and energy.
This would have been established from outset. Your more likely to be blocked once in a while if you deviate from what you initially said to bank, do high risk payments or live in a medium to high risk country.