It's surprisingly easy.
It also really depends on the auditor (the SMSF accounting company arranges this all for me).
I've heard some interesting stories but I've never had an issue or question raised.
Discussion
Cheers mate, appreciate the info. Got to get the misses set up with this as she's still in the traditional system.
Never had to do anything other than provide reports at audit time to show transaction and balances.
I haven’t had to provide wallet addresses or proof of keys.
100% self custody safely stored in the cup holder on the boat.